Commit Graph
37 Commits
Author SHA1 Message Date
Rayhaan JaufeerallyandClaude Fable 5.1 175a13d506 Hygiene: scripts, CI, docs and manifests
- scripts/in-namespace.sh set CARGO_TARGET_DIR to the empty string when
  it was unset, which cargo refuses, and dropped RUSTFLAGS, so the run
  in the namespace rebuilt what kernel-tests.sh had just built. Each is
  passed on only where set.
- The README's list of unsupported features still had route reflection
  and graceful restart, both of which exist; the command-line reference
  lacked SIGUSR1 and exit status 75; the HTTP API reference did not say
  what errors look like.
- The event stream said "missed 0 events" for the best-routes stream,
  which does not count what it missed; it leaves the count out now.
- CI lints bgp-bench with its count-memory feature, which nothing built.
- bgp-bench had two unused dev-dependencies; bgp-integration-tests had
  three dependencies that only its tests and examples use.
- install.sh updates apt before installing; two-routers.sh loses an
  unused variable; small things in the web crate.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-06 11:15:58 +02:00
Rayhaan JaufeerallyandClaude Fable 5.1 befc292215 Tidy the export limits, passive peers and status page code
Readability, no change in behaviour, but for one log line:

- The routes a peer holds from us were counted twice over, differently,
  in the exporter: once per learned-route batch and once per originated
  route. Learned::held_by_peer counts the learned ones in one place, and
  ExportLimits::exceeded_by returns the limit that was passed instead of a
  bool, so that ending the session no longer has to dig it out again with
  a default that could not happen.
- The two hold-downs for a limit passed, ours or the peer's, were two
  near-identical blocks; they are one match.
- How a session ended is put into words in one place
  (SessionEnd::reason), for the dialer's backoff and the passive peer's
  state alike.
- parse_export_limits parses one block; what a missing block means (no
  limits at the top, the top's limits for a peer) is said where it
  differs, instead of Option in and Option out.
- The startup warnings about export limits are a function of their own,
  and the peers without limits are named in one line rather than one
  line each: a router with eighty sessions does not need eighty warnings.
  The warning about a peer without a role is gone: the configuration now
  refuses one.
- Hex formatting of attribute octets is one function; the text for an
  unknown attribute is built in three plain steps.
- The exporter's test fixture returns a named struct, not a tuple.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-06 10:05:31 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 2dfc00862b Release 0.2.5
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-06 00:06:06 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 c9751883c4 Passive peers: configured, and left to connect
A session could only be configured for a peer we would then dial, every
few seconds to two minutes, for as long as it was not up. A new peer
whose side was not ready yet filled the log with failed attempts, and a
peer that opens its sessions itself was dialled for nothing.

A peer with `passive: true` is not dialled. A connection from its address
is taken as for any configured peer, and the session comes up with all
that is configured for it: role, import policy, export limits,
hold-downs. Until then the status page and /api/peers show it as
`Passive`, waiting for the peer to connect; after a session, with how
that session ended, which nothing else would say since nobody dials it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-06 00:05:54 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 910dd258fb Release 0.2.4
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-05 23:11:03 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 9cfd3f67f0 Export limits, and a role for every peer where routes are passed on
What other networks were told of rested on one thing: the Only to
Customer mark that routes from providers, peers and route servers get as
they come in. A route without it, from a session without a role or by a
mistake anywhere along the way, went to every peer, from every router of
ours, and nothing of ours stood in the way.

export_limits are a second check, independent of the roles, the marks
and the export policy. For peers above or beside us (PROVIDER, PEER,
ROUTE_SERVER, and any in another AS without a role):

- prefixes: only routes for these go out, learned or our own. With our
  and our customers' space listed, a leak of anyone else's routes goes
  nowhere above us.
- max_prefixes: if more routes were to go out than this, none of them
  does. The session ends with a Cease / Administrative Shutdown whose
  Shutdown Communication says why (RFC 9003), and the peer is held down
  for its import.hold_down_seconds, so that it is told nothing rather
  than too much. The whole table is counted before any of it is sent.

They are set at the top and hold for every such peer that has none of its
own; unlike `export`, a peer's own export policy does not drop them. A
peer's own export_limits take their place, and an empty one lifts them.
Customers, route server clients and our own routers are not limited.

A configuration in which learned routes are passed on and a peer in
another AS has no role is now refused, as is accept_unconfigured_peers
with learned routes: without a role, a peer's routes go to everyone and
it is told of everything. This used to be a warning.

At startup, a warning for each peer the limits apply to that has none,
and for each originated route the limits leave out. A metric,
bgp_export_limit_exceeded_total, counts the sessions ended for it.

The interop lab has a phase in which a customer leaks: a route outside
its space never reaches BIRD, and when more were to go than the limit,
BIRD's session ends and its log has our reason.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-05 23:10:43 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 17045a3634 Status page: tables for the kernel, communities by AS, attributes as text
The kernel section was one run-on line of interfaces and addresses. It is
now a small table of the installation state, and a table of interfaces
with their IPv4, IPv6 and link-local addresses one per line; ports that
are down and have no addresses share one line at the bottom.

Communities ran together into one block that wrapped anywhere. Each AS's
communities are now a line of their own, kept whole so that they copy,
with a hanging indent where a line wraps; pointing at a line names the AS.
Where control communities are on (now in /api/status), those of ours that
ask for something say what as a tooltip.

A rejected route's details were a fold-out that repeated the summary and
then dumped the decoded attributes as JSON. Rejected routes now have the
same columns as received ones, and both have an "other attributes" column
for what the summary had no field for, as text: aggregator, extended
communities (route targets and origins by name), AS4_PATH with its sets in
braces, originator ID, cluster list, and unknown attributes in hex. The
API has them as summary.other; the JSON stays in `attributes`.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-05 23:09:02 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 89e0c3a3e2 Release 0.2.3
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-05 18:15:28 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 b16227c51f Route reflection, with ourselves as next hop
A route learned from one router of our AS went to no other (RFC 4271
§9.2.1), so every router needed a session with every other. A router at
the end of a single link, with one session to its neighbour inside the AS,
heard only of what that neighbour learned itself, and nothing of what the
neighbour had from the routers behind it.

A peer in our own AS can now be made a route reflector client
(`route_reflector_client`, RFC 4456). What a client sends goes to all our
routers; what the others send goes to the clients. A reflected route gets
ORIGINATOR_ID (where it started, if it does not say) and our cluster ID at
the front of CLUSTER_LIST; it is not sent back to the router it started
at, nor round to a cluster it has been through, and one that comes back
anyway is refused as "route reflected back to us". The cluster ID is the
router ID unless `cluster_id` says otherwise. The two attributes are now
decoded as such rather than kept as bytes, and are never sent to other
networks.

Unlike a standard reflector, this one is the next hop of what it reflects,
as it is of everything it announces: there is no resolving a next hop
that is not a neighbour, so a client reaches what lies behind another
router through the reflector.

Only peers in our own AS can be clients; the configuration refuses the
setting for any other. Nothing changes in what other networks are told:
Only to Customer marks go along with reflected routes, and every
receiving session keeps its own max_prefixes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-05 18:10:35 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 164b1099f1 Release 0.2.2
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-05 16:39:06 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 4e945b278f Import rules: preference and communities for some routes only
The import policy did the same to every route of a session. Now `rules`
can do more to some of them: those with certain communities, those for
certain prefixes, or both. Each rule can set the local preference and put
communities on; each route takes the first rule that holds for it.

Rules see a route as the session's own statements leave it, with our
communities taken off and the session's marks put on. So a router can act
on where another router of ours learned a route, by the mark that router
put on it, and a customer's single prefix can be marked for a prepend.

Routes of one UPDATE that different rules hold for go into the table with
attribute sets of their own. An UPDATE that no rule touches is taken as
before, without its attributes being written out again.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-05 16:34:17 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 4d13336874 Release 0.2.1
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-05 16:16:45 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 72444c2706 Control communities: session groups, prepends, and only ours to give
Control communities could say which peers a route goes to, by AS. Now
they can also name sessions by group, and ask for prepends:

  L:11:P .. L:13:P   our AS once to three times more towards AS P
                     (P 0: towards every peer in another AS)
  L:20:G / L:21:G    not to / only to the sessions of group G
  L:31:G .. L:33:G   our AS once to three times more towards group G

A group is a number given to sessions in the configuration (`groups` of
a peer): those at one exchange, or those over one link. The same network
at two exchanges is one AS but two sessions, which is what steering
inbound traffic between exchanges needs. Of several prepends that apply
the most counts, on top of the session's own as_path_prepend. Functions
2 to 9, as the documentation already promised, and 100 and up stay
informational; 10 to 99 are kept for actions to come.

They are acted on where a route leaves our AS, and taken off there; our
informational communities are not. To a peer in our own AS a route goes
with them, unchanged, so that a mark put on at one router is acted on at
another. Before, they were acted on and taken off on internal sessions
too, so a route marked "to nobody" did not even reach our own routers.

And they are ours to give: the communities of our own AS (L:n, L:n:m,
and 0:n where control communities are on) are taken off every route
from a peer in another AS as it comes in, before import marks are put
on. A peer at an exchange could otherwise decide where its routes go
from us, and set our informational marks. A customer that is to steer
its own routes is given import.accept_control_communities. An UPDATE
without any of ours is still taken as it came, without being written
out again.

This changes what a customer that set control communities gets: it now
needs accept_control_communities. The transit example and the interop
lab say so; the lab also has FRR, as a customer, ask for a prepend
towards BIRD's group, and BIRD, as a provider, have its "not to" taken
off.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-05 16:12:05 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 3609451bdc Ignore our own prefixes from our own routers, and say why a route for a network of this machine is held
Two routers of an AS that both originate a prefix (anycast) each
announce it to the other over their internal session. Each took the
other's route, could not install it in the kernel, since the prefix is
on one of its own interfaces, and so held it, counted as rejected with
"next hop unreachable": a permanent rejection on a healthy session, for
a next hop that was in fact fine.

A route from a peer in our own AS for a prefix this router originates
is now ignored: not taken, not held, not counted. Only that prefix
itself; what is inside it is judged as usual. From other networks such
routes are refused as our own prefixes, as before.

A route that is held because its prefix is a network of this machine,
or inside one (an exchange's LAN prefix, say), is now counted as "prefix
is a network of this router", apart from routes whose next hop cannot
be reached.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-05 16:11:53 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 52593bb2c2 RPKI: ask a cache without data yet again soon
A validator that is still running its first validation answers a query
with No Data Available (error code 2). That ended the session, and the
next attempt came after the retry interval: 600 seconds when the cache
had not yet said otherwise, which it cannot have before it has data.
For those ten minutes after a validator started, nothing was validated.

No Data Available is now asked again after 30 seconds, or after
retry_seconds if that is shorter, and logged as information rather than
as a warning. Other failures wait as before, after trying the next
cache if there is one.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-05 16:08:19 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 9362ba9e34 Release 0.2.0
ci / check (push) Canceled after 0s
ci / docs (push) Canceled after 0s
ci / interop (push) Canceled after 0s
ci / fuzz (push) Canceled after 0s
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-04 22:48:08 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 65f136048e Graceful restart (RFC 4724, RFC 8538)
A peer that restarts keeps its routes with us, and we keep ours with our
peers while we restart, so that a restart withdraws nothing across the
network and the machine goes on forwarding. On by default for every
peer; `graceful_restart` sets the restart time we give, caps how long a
peer's routes are kept, or turns it off.

When a peer restarts: its routes are marked stale in the routing table,
and chosen as before, for at most its restart time. When it is back, what
it sends again is fresh, and the stale routes of a family go at its
End-of-RIB marker, or after the cap; at once for a family whose
forwarding it did not keep. Only a connection that failed counts as a
restart, and, with RFC 8538 agreed, an expired hold timer or a
NOTIFICATION other than a Hard Reset. The stale mark is a bit of the
route's word that selection never looks at.

When we restart: SIGUSR1 leaves the kernel's routes where they are,
closes the sessions without a word where graceful restart is agreed, and
exits with status 75, on which the systemd unit starts us again. The next
start finds the routes in the kernel, says so in its OPENs (R, and F where
forwarding was kept), and has them go once every peer has sent its
End-of-RIB. Our own End-of-RIB markers for learned routes wait for that
too. SIGTERM still stops for good, now with a Hard Reset where RFC 8538 is
agreed, as are errors of ours.

The status page and API show what was agreed with each peer, the routes
kept while a peer restarts, and which routes are stale. Tested against
FRR and BIRD in a new phase of the interoperability lab, and with routes
kept in a real kernel over a restart.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-04 22:43:47 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 acecc22f48 Status page: count rejected announcements, and name AS numbers
The "refused" column counted rejected announcements since the start, not
routes, which made two peers that send the same routes look different
when one of them re-sends more often. It is now "rejected announcements",
with the held routes, the number that compares, beside it as "held now".
The page says "rejected" throughout, as the documentation and metrics do.

Rows are highlighted under the pointer, and pointing at an AS number
shows its holder's name, which the browser asks RIPEstat for. The daemon
looks nothing up; the monitoring page says what the browser sends where.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-04 22:43:36 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 efb2d81a50 Reject blackhole requests with a reason of their own
ci / check (push) Canceled after 0s
ci / docs (push) Canceled after 0s
ci / interop (push) Canceled after 0s
ci / fuzz (push) Canceled after 0s
A route with the BLACKHOLE community (RFC 7999) asks for the traffic to
its prefix to be dropped. Exchange route servers pass these on as host
routes with the exchange's blackhole address as next hop, and they were
rejected as "prefix too specific", which hid what they are.

Routes from EBGP neighbors with BLACKHOLE are now rejected as "blackhole
request", whatever their length. One short enough to pass would have
been taken as an ordinary route, sending the traffic to the blackhole
next hop: the request honoured without anyone having chosen to. Acting
on blackhole requests is not supported; the import policy page and the
standards list say so.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-04 01:03:16 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 bd674002a2 Keep the path attributes of rejected routes, and show them
A rejected route was recorded with its prefix, reason and AS path, which
is not enough to tell why a neighbor sent it: whether a /32 is a
blackhole request, which communities a leaked route carries, which
network marked it Only to Customer.

Each recorded rejection now keeps the attributes of the UPDATE it came
in, without the NLRI of MP_REACH_NLRI and MP_UNREACH_NLRI, and its next
hop. The attributes are copied once per UPDATE, only when a route of it
is rejected, and shared by its rejected routes. A route rejected later,
when the RPKI data changes, has the attributes it was stored with.

/api/routes/rejected gives them as `summary` and `attributes`, as for
received routes, and the status page shows them under "show" in each
row of the refused routes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-04 01:03:16 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 e1d819d629 Add a script that builds a static Linux executable
scripts/build-static.sh builds the daemon for x86_64 Linux against
musl, as one executable without dependencies to copy to a router. It
finds a musl C compiler for jemalloc (musl-cross on macOS, musl-gcc on
Linux), and uses its ar and ranlib too: with the host's, a build from
macOS gets an empty libjemalloc.a and fails to link. It prints the
revision and the SHA-256 of the result.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-04 01:03:16 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 361c48f656 Use jemalloc as the daemon's memory allocator
A full table from several neighbors means millions of small, long-lived
allocations that are replaced as routes change. jemalloc keeps the
resident size of such a workload closer to what is in use than the
system allocator does, glibc's in particular, and does not depend on
the C library the binary is linked with. Not on MSVC, which jemalloc
does not support.

Building now needs a C compiler and make; the installation page says
so.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-04 01:03:16 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 9ce81a873e Docs: show the front page photograph in its own colours
The blue two-colour treatment is replaced by the photograph's own
colours, slightly darkened, under a neutral shade that keeps the text
legible.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-03 21:35:36 +02:00
Rayhaan JaufeerallyandClaude Opus 5.5 dc275f99d7 Add a documentation website, built with Zola
ci / check (push) Canceled after 0s
ci / docs (push) Canceled after 0s
ci / interop (push) Canceled after 0s
ci / fuzz (push) Canceled after 0s
The documentation moves from READMEs into a site in docs/: getting
started, a user guide, operations, a reference, and development pages,
written in the style of network vendors' documentation (docs/STYLE.md).
bin/bgp/README.md and docs/RFCs.md are folded into it.

- A theme of its own in the International Typographic Style, in blues,
  with self-hosted Inter and JetBrains Mono, search over Zola's index,
  dark mode, and no resources loaded from other hosts.
- Example configurations in docs/examples/, shown on the pages and
  checked with `bgp --check` in CI.
- A test that fails when a field of config.proto is missing from the
  configuration reference.
- A CI job that builds the site; Zola fails on broken links and anchors.
- A hardened systemd unit, tried under systemd with kernel routes on.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-03 15:12:43 +02:00
Rayhaan JaufeerallyandClaude Fable 5.1 1e2e8f2d86 Pass learned routes on to peers, with marks and control communities
What was to be scripted is configuration, done natively:

- import { add_communities, add_large_communities, remove_communities,
  local_pref }: every route taken from a peer is marked (where it was
  learned, say), with nobody else's word for our marks taken, and given
  its preference, which selection goes by.
- export { add_communities, add_large_communities, remove_communities,
  as_path_prepend, learned_routes }, for a peer or for all that have none
  of their own.
- control_communities: the communities by which routes say which peers
  they are passed on to, as exchanges' route servers have them (0:P, L:P,
  0:L, and the large forms L:0:P, L:1:P, L:0:0), taken off as the route
  goes on.

And what the last of these is for: with export.learned_routes a peer is
told the best route of every prefix the others announced. The rules are
BGP's and cannot be turned off: not back where it came from, not to a
peer whose AS is on the path, not between two internal peers, not past
NO_EXPORT or NO_ADVERTISE; our AS on the path and ourselves as next hop
to another network, LOCAL_PREF to our own; to a route server's client
the path, MED and next hop as they came (RFC 7947). Which routes go where
follows from the roles of RFC 9234: a route that came down or across goes
on down only, so that with roles on every peer this makes us transit for
our customers and nothing else. A peer without a role is told everything,
and the daemon says so at startup.

Each session follows the table's best routes with a reader and keeps the
prefixes it has announced, so that it can withdraw them. Routes that go
out alike go in one UPDATE: changes are gathered for 50 ms first, and a
table that is given out anew is gathered whole (at most four sessions at
a time; it is tens of megabytes). For that to work the table's journal
had to give out together what was written together: every change now
carries a time on a table-wide clock, a reader's pass reads every shard
up to one time, no further than the changes that are complete in every
shard, and a resync takes its places in the journals as of one time.

One peer sending 1.23 M routes over a session, another told of them:
in our table after 0.47 s, all heard after 2.1 s, four routes an UPDATE.
The lab has a phase, transit: FRR as our customer and BIRD as our
provider, routes each way with the right paths and marks, one kept back
by a community, and pings between their networks through us.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-02 23:48:08 +02:00
Rayhaan JaufeerallyandClaude Fable 5.1 f1d80c66df Do not choose a route whose next hop cannot be reached (RFC 4271 §9.1.2.1)
Where routes go into the kernel, a route the kernel could not be given
is no longer taken into the table: its next hop is no neighbor on any
interface, or its prefix is a network the machine is itself on. Such a
route used to be able to win selection and then leave its prefix without
a route in the kernel, though another peer had one that worked.

It is held aside the way an RPKI-invalid route is, and by the same
means: judged on arrival against the interfaces as the kernel last
described them, looked for in the table when they change, and taken
from what is held when its next hop can be reached. The fib publishes
the interfaces for this; the next hop is resolved once for an UPDATE
and not for each of its routes.

The lab has a phase, nexthops: FRR's better route with a next hop that
is nowhere is held and BIRD's is installed, and they change places as
an address comes and goes.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-02 20:29:31 +02:00
Rayhaan JaufeerallyandClaude Fable 5.1 3d946c32ce Code health after review: docs, metrics, structure, one more fuzz target
What the code-health review found, and what a fuzz target written for it
found in its first seconds.

- A set of attributes with the same attribute twice is refused by the
  routing table. Its readers (the selection key, the path, the next hop)
  could each take a different one of the two. The decoder never lets one
  through; the new fuzz target `attrs` found that the table would.
- bgp_peer_up{peer}, to alert on a peer going away, and bgp_build_info.
  Every metric is there from the first scrape. Alerts for a peer down,
  hijack attempts and kernel errors are in the README.
- `bgp --check config` validates a configuration without starting, and
  `--version` says which build it is. CI runs the first on the example
  configuration, which a test now also parses with its commented fields
  put in; the example had to learn about the next hop check.
- Path attributes have a module of their own, packet::attributes,
  re-exported from packet::message as before.
- policy::From, which shadowed the trait, is RouteSource. The server's
  connection, dialer and fsm modules are private. Logging arguments live
  in the binary; the server library no longer depends on clap.
- One is_unicast_link_local (the standard library's) instead of two of
  our own; SelectionKey::origin(); one place where an Import is made.
- READMEs say what the daemon does today rather than what it did not do
  a year ago. Documentation links are checked in CI. Unused dependencies
  and bgp_web::serve are gone; the Docker build is --locked and does not
  ship the fuzz corpus.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-02 19:31:19 +02:00
Rayhaan JaufeerallyandClaude Fable 5.1 9ca86ede2f Harden import, the kernel task and the RTR client after review
Three independent reviews (hijack resistance, reliability, code health)
of the whole tree. This is what they found that could let a bad route in
or take the daemon down.

Hijacks:
- A route had two paths on a two-octet session, AS_PATH and AS4_PATH,
  read in two places by two rules. A peer could make the origin checked
  on import differ from the one checked at revalidation, and get an
  RPKI-invalid route into the table. AS4_PATH is now merged into AS_PATH
  once, on receipt (RFC 6793 §4.2.3), and nothing else knows of it.
- The next hop is judged on import: it must be usable, agreed on
  (RFC 8950), and by default the peer itself.
- Our own originated prefixes are not taken from other networks.
- A route for a network the machine is on is never put in the kernel.
- Paths with an AS_SET are refused (RFC 9774).
- A configured peer gets one session, not one per BGP Identifier.
- More IPv6 special-purpose prefixes are bogons.

Reliability:
- A batch of requests the kernel refused could overflow the netlink
  socket and end the daemon. The socket has room now, a lost answer or a
  silent kernel means asking what is there, and neither is fatal.
- Working the routes out again within the grace period after a restart
  no longer drops the routes being kept.
- That work can no longer be put off for ever by interface changes.
- Peers whose sessions keep failing are slowed down.
- Unused attribute sets are swept when they pile up, not only each
  minute.
- Log lines a peer can cause are said once in a while.
- An RTR answer is bounded in size and time; data cannot expire between
  two refreshes.
- The shard of a key is taken from a stirred hash: neighbouring bits of
  the hash proved alike for prefixes in a row. The test that showed it,
  failing one run in sixteen, is deterministic now.

The lab has a phase, hijacks, in which FRR tries the first three.
route::apply is a struct with methods instead of nested closures, and
the kernel task's loop is shorter.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-02 19:13:40 +02:00
Rayhaan JaufeerallyandClaude Fable 5.1 fd2248feb5 Peer at link-local addresses: fe80::1%eth0
A peer's endpoint may be a link-local IPv6 address with the interface it
is on. Such a peer is the address and the interface together, wherever
peers are told apart: admission, collisions, hold-downs, the refusal log,
the status page. The interface is looked up by name each time it is
needed, so one that appears later or is made anew is found.

Our routes go out with our link-local address in both places of
MP_REACH_NLRI's next hop, as FRR sends its own. A peer's link-local next
hop is taken alone, twice, or after "::" (BIRD), and resolved in the
kernel on the interface of the session rather than by looking fe80::/64
up, which every interface has.

The lab has a new phase, linklocal: sessions with FRR (by interface, with
radvd beside the daemon) and BIRD over a LAN with link-local addresses
only, both families, pings across, the interface down and up.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-02 18:24:13 +02:00
Rayhaan JaufeerallyandClaude Fable 5.1 92e013ca01 Carry IPv4 routes over IPv6 sessions with IPv6 next hops (RFC 8950)
For a link that has only IPv6 addresses.

- The Extended Next Hop capability is offered on every session over IPv6
  whose families include IPv4 unicast, and used if the peer offers it too.
  Nothing to configure.
- On such a session our IPv4 routes go out in MP_REACH_NLRI with the
  session's IPv6 address as next hop, and are withdrawn in
  MP_UNREACH_NLRI. Without the agreement they are not sent, as before.
- IPv4 routes are read with an IPv6 next hop, global or global with
  link-local.
- The kernel installer resolves an IPv4 route's IPv6 next hop like any
  other and installs it: by way of an IPv6 nexthop object, or with RTA_VIA
  where routes carry their own gateway.

Tested against a real kernel in both modes, with a link-local next hop
too, and in the lab against FRR and BIRD: the new `v6only` phase takes
the IPv4 addresses off the exchange LAN, runs one IPv6 session with each
router for both families, and pings IPv4 across.

Sessions between link-local addresses are not supported yet.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-02 17:58:03 +02:00
Rayhaan JaufeerallyandClaude Fable 5.1 1fc44798b7 Install best routes in the Linux kernel over netlink
New crate bgp-fib. It follows the routing table's best routes and keeps
the kernel's routing table the same, and learns the machine's interfaces
and addresses from the kernel, which is what says whether a next hop can
be reached.

- netlink: the rtnetlink messages used (routes, addresses, links, errors),
  as bytes and back. No I/O; property tested and fuzzed.
- interfaces: what is directly reachable, and from which interface.
- plan: what to ask the kernel for, given the best routes and what the
  kernel has. No I/O; tested against a model kernel.
- kernel (Linux only): the sockets and the task. Requests go in batches;
  routes of ours found at startup are kept if still right and removed if
  not; a change of interfaces has every route worked out again; a clean
  stop removes our routes.

Only routes marked proto bgp with the configured table and metric are
ever touched. A best route is installed if its next hop is a neighbor;
next hops further away are not resolved through other routes yet, and
such prefixes are counted and shown instead.

Configured with `kernel { table metric }`; off by default. The daemon
needs CAP_NET_ADMIN and stops if the kernel refuses it. On shutdown it
closes sessions and then removes its routes.

/api/kernel and the status page show installed, unresolved and refused
counts, the last error and the interfaces; five bgp_kernel_* metrics.

Testing: scripts/kernel-tests.sh runs, in network namespaces of their
own and with only the capabilities the daemon needs, the installer
against `ip route`, the daemon with a peer, and two daemons that route
for each other with pings across over IPv4 and IPv6.
scripts/linux-vm.sh runs that, or anything else, in a Lima VM from
macOS. CI runs the kernel tests and fuzzes the netlink decoder.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-02 15:15:43 +02:00
Rayhaan JaufeerallyandClaude Fable 5.1 f9ef781d51 Check roles in OPEN and prevent route leaks with Only to Customer (RFC 9234)
A peer's configured role now does three more things:

- Our OPEN carries the BGP Role capability with what we are to the peer.
  A peer whose own says it is something that does not pair with that, or
  that sends two different roles, is refused with OPEN Message Error /
  Role Mismatch. A peer that says nothing is accepted unless require_role
  is set. A role on a peer in our own AS is a configuration error.
- Routes from a provider, a peer or a route server are marked Only to
  Customer on the way in if they are not already, and our routes are
  marked on the way out to a customer, a peer or a route server client.
- A marked route from a customer or route server client, or from a peer
  with someone else's mark, is a leak and is refused. No policy setting
  turns that off.

The packet crate gains the Only to Customer attribute (malformed:
treat-as-withdraw), and the Role Mismatch subcode is corrected from 8 to
11.

The status page shows whether the peer confirmed its role.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-02 14:27:36 +02:00
Rayhaan JaufeerallyandClaude Fable 5.1 8086aa994f Verify AS paths with ASPAs, over RTR version 2
Origin validation says who may originate a prefix and nothing about the
rest of the path: it does not catch a route leak, nor a hijack that keeps
the right origin at the end of a made-up path. ASPAs, in which a network
lists its providers, do.

bgp-rpki:
- aspa: the ASPAs and the upstream and downstream verification procedures
  of draft-ietf-sidrops-aspa-verification-24, tested against the draft's
  wording as written.
- rtr: protocol version 2 (draft-ietf-sidrops-8210bis-23) with the ASPA
  PDU and the new error codes.
- client: asks for version 2 and falls back to whatever older version the
  cache speaks; keeps ASPAs with the VRPs, applied whole or not at all;
  publishes which customers' ASPAs changed; tells the cache why it is
  being left (Error Report); does not ask one version's serial of another.

Server:
- A peer has a role (provider, customer, peer, route server, route server
  client), which decides how its paths are verified. Without one they are
  not.
- A route whose path is invalid is refused ("ASPA invalid") and held, like
  one with an invalid origin; accept_aspa_invalid exempts a peer.
- When ASPAs change, routes in the table whose path has a changed customer
  on it are verified again, and held routes are released when they pass
  both checks.
- The revalidator finds a route's peer by index instead of searching a
  list for every route.

The status page and API show each peer's role, each route's path validity,
the number of ASPAs and the RTR version in use; bgp_rpki_aspas is on
/metricz.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-02 14:12:59 +02:00
Rayhaan JaufeerallyandClaude Fable 5.1 bdaf226a16 Validate route origins against the RPKI and refuse invalid routes
With rpki { caches { ... } } in the configuration the server keeps the
validated ROA payloads of a validator and validates every route from a
peer outside its own AS (RFC 6811). An invalid route is refused, unless
its peer has accept_rpki_invalid. Valid and not-found routes are taken;
validity does not otherwise enter route selection.

Validity is not settled when a route arrives: the data changes every few
minutes. The routes follow, without the peer sending anything again.

- A route refused as invalid is held by its session, out of the table.
  When the data changes the session looks at what it holds, and what is
  no longer invalid goes into the table. A held route is the peer's to
  withdraw or replace like any other.
- A route in the table that becomes invalid is found by a task that
  looks through the table when the data changes, at the prefixes the
  changed VRPs cover, and is taken out and held by its session.
- If the data expires because no cache confirms it, nothing is invalid
  any more and everything held is taken.
- A session holds at most 200,000 routes; past that it asks the peer for
  a route refresh when the data changes.

So that the table can be looked through without parsing attributes, an
attribute set's key now has the route's origin AS. Memory per route is
unchanged at 52 bytes on the real table.

Shown: /api/rpki and a section of the status page with the cache, its
state and the age of the data; each route's validity; each peer's count
of held routes. Refusals are recorded under "RPKI invalid". Metrics:
bgp_rpki_vrps and bgp_rpki_updates_total.

Also: Negotiated says whether the peer supports route refresh, and
docs/RFCs.md is brought up to date.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-02 13:39:40 +02:00
Rayhaan JaufeerallyandClaude Fable 5.1 630c175918 Rework the speaker: sans-I/O FSM, sharded table, RFC 7606, ADD-PATH
The work of the speaker-cleanup branch as one commit; the branch keeps
the step-by-step history.

Sessions
- The state machine is a pure function from events to actions, driven by
  one task per connection. Idle, Connect and Active belong to a dialer
  that keeps configured peers up with backoff.
- Capabilities are negotiated: address families, four-octet AS numbers
  with AS_TRANS and AS4_PATH, route refresh, ADD-PATH per family and
  direction.
- Collision detection per RFC 4271 section 6.8, by address and
  identifier.
- Connections are taken only from configured peers, a few per address.
- A panic in a session is contained and answered with a Cease; a core
  task that stops shuts the server down with a Cease to every peer.
- Writes that make no progress are given up (RFC 9687).

Codec
- Malformed UPDATEs are handled as RFC 7606 says: treat-as-withdraw,
  attribute discard, or session reset, with the NOTIFICATION to send.
- Address families are open types; any can be named and ignored.
- Prefixes are fixed-size values, normalised, with path identifiers.
- Lengths are filled in after writing; one definition of each type code.
- Property tests and fuzz targets for every decoder.

Routing table
- Adj-RIBs-In and Loc-RIB in one sharded table that sessions write to
  directly. Routes are sixteen bytes; attribute sets are interned in
  wire form. Best-path selection per RFC 4271 section 9.1.2.2 with
  deterministic MED.
- A journal per shard lets followers read changes at their own pace;
  one that falls behind is resynchronised.
- On a RIPE RIS dump of 148 peers and 39.3M routes: loaded in 2.0 s on
  12 cores, about 52 bytes a route.

Announcing
- Originated routes come from the configuration. Each session has its
  own exporter with an Adj-RIB-Out, so a slow peer delays only itself.
- Routes to a peer in our own AS have an empty path and a LOCAL_PREF.

Operations
- HTTP status page, JSON API, event stream and Prometheus metrics.
- Benchmarks on synthetic and real tables.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-02 12:35:54 +02:00
Rayhaan JaufeerallyandClaude Sonnet 4.6 1ec60255ea feature: BGP server, FSM, Adj-RIB-In actor, and integration tests
- Implement passive-side BGP FSM (OpenSent → OpenConfirm → Established)
  with hold timer, keepalive timer, and NOTIFICATION on expiry
- Add bgp-server crate: config validation, TCP listener accept loop
  (BgpServerBuilder → BgpServer), connection dispatch
- Add bgp-rib crate: Adj-RIB-In actor owning route state with event
  broadcast for streaming consumers and snapshot for introspection
- Wire Adj-RIB-In into FSM: announce/withdraw on UPDATE for both legacy
  IPv4 NLRI fields and MP_REACH/MP_UNREACH path attributes
- Add bgp-integration-tests crate with 15 end-to-end tests covering
  session establishment, timers, UPDATE handling, and RIB introspection
- Fix require_empty! macro bug in open.rs (checked wrong buffer)
- Fix FourByteAsn capability parser returning consumed buffer as remainder
- Fix tracing subscriber not being installed in TracingArgs::install
- Expand docs/RFCs.md with full implementation status across 15 RFCs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-19 00:21:51 +02:00
Rayhaan Jaufeerally 5ae8f6e249 Cleanup and implementation of Update / Notification parser / serializers. 2026-04-18 12:58:51 +02:00