Set tun.staged.workers to a positive count on Linux, with tun.use_offloads
enabled, to move encryption off each tun reader. The reader filters and
reserves counters for a whole read, hands the batch to that many encrypt
workers, and an ordered sender flushes the batches in read order. Eight slots
per routine bound the batches in flight; a full pipeline blocks the reader.
Zero workers, the default, keeps today's inline path, as do tun queues that
cannot hand off their read buffer and builds whose AES-GCM needs nonce-ordered
encryption (BoringCrypto, FIPS).
IMPORTANT: staged senders need peers with the 8192-entry replay window of
master. Released v1.11.x peers use 1024 and will drop reordered batches. The
window is not negotiated.
Readers keep today's pinning. The sender is only pinned with an explicit
tun.cpu_affinity: sender i uses entry i+1, unless that is its reader's CPU,
so a one-entry list leaves the sender unpinned rather than sharing it: two
busy transmit threads on one CPU serialise (eight TCP streams over 100 GbE
fell from 25.9 to 22.8 Gbit/s). Without a list the sender is not pinned. Placing it by queue index on a
hybrid CPU put it on an efficiency core, and one TCP stream over 100 GbE
reached 18.6-19.6 Gbit/s pinned against 20.2-20.6 unpinned.
New API, each needed across a package boundary:
- tio.Offload.SwapRxBuf hands the buffer of the last Read to the reader and
reads into the one given. It is a method on the concrete queue, found through
an unexported interface in nebula, so tio.Queue and its other
implementations are unchanged.
- batch.SendBatch.Reset drops queued packets without sending, for a sender
whose sockets are already closed; Flush now uses it.
Metrics, registered only for active pipelines: flow.tx.batches counts reads
handed to the sender, flow.stage.{tx_read,tx_encrypt,tx_send}.q<N>.busy_ns the
elapsed busy time of each stage, to find the limiting one.
Tests cover ordering and counters under backpressure with both ciphers (AES
skipped where nonce order is required), read errors with batches in flight,
shutdown, exhaustion, relays, fallback, firewall parity, and the actual reader
and send thread affinity for every placement, with pinning on and off: the
sender is pinned only to an explicit entry other than its reader's CPU.
Build on the inside-packet filtering split with shared preparation and encryption helpers for inline and reserved sends. Reserve each batch’s per-tunnel counter range before encryption, including relay counters, without enabling staged processing yet. Test reserved encryption against a real receiver and check segmentation counts.
gvisor's arm64 race-build compare-and-swap (pkg/sync/race_arm64.s)
loaded the new value into the register meant for the old one (R1
instead of R2), so it never succeeded. Sleepers could not commit to
parking and spun: under -race on arm64 every idle service netstack
busied about 14 cores, and TestService's static host lookup of
localhost missed its 250ms timeout and stalled for the 30s static_map
cadence. Fixed in gvisor 1b2946c4fa.
Go 1.27.2 is now the minimum because gvisor's go branch requires it.
golangci-lint is bumped to v2.14, the first release that can read
go1.27.2 export data.
Tailscale with an exit node treats every interface address prefix as an
attached LAN and either claims it or excludes it, and configd then rewrites
the matching route away from nebula's utun. Interfaces holding a single
address are skipped, so assign /32 and /128 and add the network route
ourselves for both families.
* examples: set socket buffers and raise tun tx_queue
* examples: use the default tcp max window for socket buffers
* examples: note buffers are linux only, clarify tx_queue default
* tun: default tx_queue to 5000
On a domain-joined Windows host the DNS Client registers every adapter's
addresses under the host name in AD DNS when "Register this connection's
addresses in DNS" is on, which is the default for a new adapter. When the
Nebula adapter registers, LAN clients that are not on the overlay resolve
the host name to its overlay IP and RDP, SMB and PowerShell Remoting to it
fail intermittently, with nothing pointing at the tunnel as the cause.
Windows registers on address assignment, periodically, and on every
ipconfig /registerdns.
Right after the wintun adapter is created and before Activate assigns any
address, write RegistrationEnabled=0, DisableDynamicUpdate=1 and
MaxNumberOfAddressesToRegister=0 under both the Tcpip and Tcpip6
Parameters\Interfaces\{GUID} keys. The adapter checkbox alone has proven
insufficient in practice, as has disabling dynamic updates alone, so all
three are set, matching what Tailscale and NetBird do. A failure to write
the keys is logged as a warning and does not fail adapter creation.
StartHandshake returned a hostinfo with no RemoteList; handleOutbound attached
one lazily on its first tick. Anything that touched the pending host before
then, notably create-tunnel -address, dereferenced nil and took the daemon
down. StartHandshake now attaches the lighthouse's list as it builds the
hostinfo. To keep the surrounding locking sound, a lighthouse now resolves a
punch target before taking the querier's RemoteList lock, and closeTunnel
deletes the host and evicts its RemoteList under a single hostmap write lock so
a completing handshake cannot land in between. The lock order, now documented
on the handshake manager mutex, is hostmap, then handshake manager, then
lighthouse, then RemoteList; no RemoteList lock is ever held across a hostmap
lookup.
newTunFromFd was a stub on darwin, so an embedder handed a utun by the OS had
no way to use it. A darwin network extension is given exactly that:
NEPacketTunnelProvider creates the device and applies addressing, mtu and
routes from its network settings, and a sandboxed extension cannot change them
afterwards. Adopting that fd means everything about moving packets is shared
with newTun and only the setup differs, so the tun tracks whether the host owns
it and leaves the system routing table and interface config alone when it does.
Co-authored-by: Nate Brown <nbrown.us@gmail.com>
The goroutines Main starts stop only when its context does, and only a caller
holding the Control can arrange that. Cancelling solely on error left a config
test, which returns no Control and no error, with the lighthouse query worker
and a hostname resolver per dns named static host running for the life of the
process. Every embedder that validates a config in process rather than by
exec'ing pays for that on each config load, dnclient and the apple clients
included.
Co-authored-by: Nate Brown <nbrown.us@gmail.com>
* Add script to backport a merged PR to a release branch
.github/backport.sh cherry-picks a merged PR's commit onto a release
branch and opens a backport PR mirroring the shape of #1842.
- Infers the target release from the PR's milestone (v1.12.0 -> release-1.11);
an explicit target-version argument overrides it.
- Requires a clean working tree (untracked files allowed) before starting.
- Prompts with the exact push and gh pr create commands before running them.
- Sets the new PR's milestone to the highest open v<target>.* milestone.
- Removes the needs-backport label from the original PR once the backport opens.
- Supports --continue to resume after resolving cherry-pick conflicts.
* cleanup
* just fetch all of origin
We need to ensure we have MERGE_SHA available too