Files
firezone/rust/connlib
Thomas Eizinger d1eb1961dc fix(connlib): recalculate overlapping CIDR routes less often (#7592)
Firezone needs to deterministically handle overlapping CIDR routes. The
way we handle this is that more specific routes are preferred over less
specific one. In case of an exact overlap, the sorting of the resource
ID acts as a tie-breaker: "Smaller" resource IDs preferred over "larger"
ones. This ensures that regardless of which order the resources are
added / enabled in, Firezone behaves deterministically.

In addition to the above rules, existing connections to Gateways always
have precedence: In other words, if we are connected to resource A via
Gateway 1 and resource B exactly overlaps with A yet needs to be routed
to Gateway B and B < A, we still retain resource A in order to not
interrupt existing connections.

When a connection to a Gateway fails, these mappings are cleaned up. The
proptests seeds added in this PR identify a routing mismatch in case a
(relayed) connection is cut, followed by adding a non-CIDR resource:
`connlib` recalculated the CIDR routes as part of adding the new
resource, even though the CIDR resources didn't actually change. This
could potentially result in a connection suddenly being routed to a
different Gateway despite nothing about that resource changing.

To fix this, we add a check for updating the CIDR routes and only
perform it in case CIDR resources get changed.
2025-01-03 14:35:32 +00:00
..

Connlib

Firezone's connectivity library shared by all clients.

Building Connlib

You shouldn't need to build connlib directly; it's typically built as a dependency of one of the other Firezone components. See READMEs in those directories for relevant instructions.