mirror of
https://github.com/GNS3/gns3-server.git
synced 2026-10-12 21:45:41 +03:00
90bcb32473
Switch-to-switch links were the last shape left on the relay: the switch fast path works by absorbing the *peer's* anchor, and a switch has none — its ports are its own bridge, and a kernel interface belongs to exactly one bridge, so two bridges cannot be joined by enslaving anything. Join them with a veth pair instead: one end per bridge, each side enslaving its own end and applying its own port mode to it — an access port on one side and a trunk on the other behaves like the real cable it models. uBridge's docker create_veth/delete_veth (the primitive every Docker adapter is already born from) creates and destroys the pair; the names derive from the link id (utils.kernel_anchor.kernel_cascade_names), so each side computes its own end and the names survive a restart. The pair belongs to the link, and the two ends are wired by two independent uBridge processes — the project-open batch drives different nodes concurrently — so the protocol is order-free: both sides create the pair when their own end is missing (one create wins; the loser's failure is re-checked against the kernel and "the pair is there" is not an error), and either side's teardown destroys it (deleting one veth end takes the other with it, so both converge on the same gone pair and the second delif answers ENOENT). A pre-existing end — this switch restarted, or a leftover from a previous life of the link id — is reused rather than recreated, because the other end may still be a live port of the peer switch; a stale tc qdisc is all a reused end can carry. No new wire format was needed: a cascade is an anchor NIO on both ends, the absorbed-anchor case plus the peer end's name. That also corrects the filter routing — the single-sided rule exists because an absorbed anchor is one interface, while a cascade has one per switch, so impairments go to both ends like any other kernel link. Tests: the wire format, the eligibility flip and the both-ends re-push on node start (controller); the naming contract (utils); the switch-side lifecycle — create, reuse, lost create race, delete destroys the pair (compute routes). Drive-by: the relay filter test's compute mock carried no awaitable `put`, so tests/controller/test_kernel_datapath_link.py failed when run alone while an argument-less full run passed; callers now get one.