a1415dbc05
* [client] Add tests for the ICEBind open and close races Running many embedded clients in one process intermittently wedges interface creation. A goroutine dump taken from 50 clients shows ten of them parked for seven minutes in Device.IpcSet, in closeBindLocked waiting on device.net.stopping.Wait, holding device.net while every other device goroutine queues behind it on Device.Up. Open writes s.closed and Close reads it with no synchronisation, and Close also closes s.closedChan without the mutex that Open swaps it under. Two Closes can both pass the check and close the same channel, and a Close racing an Open can mark the bind closed while a live channel and live receive functions remain, after which every later Close takes its early return and runs neither close(closedChan) nor StdNetBind.Close. The receive functions never stop, so stopping.Wait never returns. These tests do not fix that. The first pins the contract closeBindLocked depends on and passes today. The other two fail under -race, reporting the races at the three sites above, and pass again once closed and closedChan are guarded consistently. * [client] Release parked receivers so reopening a bind cannot stall receiveRelayed held closedChanMu for the whole of its blocking select, so a parked receiver kept the read lock indefinitely and Open could never take the write lock it needs to install a fresh closedChan. wireguard-go reaches Open from Device.IpcSet and Device.Up with device.net held, so the stall took the device lock with it: interface creation never finished, every other device goroutine queued behind Device.Up, and Engine.Start never returned. Callers now copy the channel under a short read lock and select on the copy. Copying alone would stand a new trap in the same place, because an Open that follows an Open leaves the previous generation parked on a channel no later Close can reach, so Open now closes the outgoing channel before swapping it. closed and closedChan are also updated together under that mutex. Read and written apart, Close could see a stale closed and skip both close(closedChan) and StdNetBind.Close, leaving every receive function running and wedging closeBindLocked on device.net.stopping.Wait, or two Close calls could pass the check together and close the same channel twice. TestICEBindOpenDoesNotBlockOnParkedReceiver fails without this change, without needing the race detector. The other three cover the surrounding contract and report the state races under -race. * [client] Make the bind lifecycle transition atomic and tighten its tests Review caught that the previous commit moved the torn transition rather than removing it. Open published the new generation before calling StdNetBind.Open, so an Open rejected because the bind was already open had already signalled the outgoing generation, and a Close arriving in that window could mark the bind closed while the same call went on to install live sockets. Every later Close then returned early and never shut them down. Open now calls StdNetBind.Open first, so a failure leaves the current generation untouched, and both Open and Close hold the lock across the whole transition. Ordering is safe: StdNetBind.Open reaches muUDPMux through createReceiverFn, and no path takes muUDPMux before closedChanMu. The tests were also weaker than they read. The stress test claimed to cover a stale channel but only ever raced two Closes, and the concurrency test left overlap to goroutine start order. Both now gate their goroutines on a common start, the stress test races an Open against the Closes, and both assert the surviving generation channel is actually closed. Waiting on receive functions to be entered replaces part of the sleep in the reopen probe, and teardown bounds its Close so a regression fails the assertion instead of hanging. Two of the four now fail without the fix and no race detector, the stress test by reproducing close of a closed channel at the Close early return. * [client] Fail the reopen probe when its teardown does not complete closeBounded swallowed its timeout and the cleanup discarded what receiversStopped returned, so the bounds added in the previous commit only stopped teardown hanging. A wedged Close or a parked receiver would have left the test green with a leaked goroutine, which is the failure this test exists to catch. closeBounded now reports whether Close returned, and cleanup fails the test on either bound.
Start using NetBird at netbird.io
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🤖 NetBird Agent Network (Beta)
Identity-aware access control for AI agents — keyless access to LLM APIs and private resources over the encrypted NetBird tunnel. See
agent-network/or read the docs at netbird.ai.
NetBird combines a configuration-free peer-to-peer private network and a centralized access control system in a single platform, making it easy to create secure private networks for your organization or home.
Connect. NetBird creates a WireGuard-based overlay network that automatically connects your machines over an encrypted tunnel, leaving behind the hassle of opening ports, complex firewall rules, VPN gateways, and so forth.
Secure. NetBird enables secure remote access by applying granular access policies while allowing you to manage them intuitively from a single place. Works universally on any infrastructure.
https://github.com/user-attachments/assets/10cec749-bb56-4ab3-97af-4e38850108d2
Self-host NetBird (video)
Key features
Quickstart with NetBird Cloud
- Download and install NetBird at https://app.netbird.io/install.
- Follow the steps to sign up with Google, Microsoft, GitHub or your email address.
- Check the NetBird admin UI.
Quickstart with self-hosted NetBird
This is the quickest way to try self-hosted NetBird. It should take around 5 minutes to get started if you already have a public domain and a VM. Follow the Advanced guide with a custom identity provider for installations with different IdPs.
Infrastructure requirements:
- A Linux VM with at least 1 CPU and 2 GB of memory.
- The VM should be publicly accessible on TCP ports 80 and 443 and UDP port 3478.
- A public domain name pointing to the VM.
Software requirements:
- Docker with the Compose plugin (Compose v2 or higher). See the Docker installation guide.
Steps
- Download and run the installation script:
export NETBIRD_DOMAIN=netbird.example.com; curl -fsSL https://github.com/netbirdio/netbird/releases/latest/download/getting-started.sh | bash
A bit on NetBird internals
- Every machine in the network runs the NetBird agent, which manages WireGuard.
- Every agent connects to the Management Service, which holds network state, manages peer IPs, and distributes updates to agents.
- Agents use ICE (via pion/ice) to discover connection candidates for peer-to-peer connections.
- Candidates are discovered with the help of STUN servers.
- Agents negotiate a connection through the Signal Service, exchanging end-to-end encrypted messages with candidates.
- When NAT traversal fails (e.g. mobile carrier-grade NAT) and a direct p2p connection isn't possible, the system falls back to a Relay Service and a secure WireGuard tunnel is established through it.
See a complete architecture overview for details.
Community projects
- NetBird installer script
- netbird-tui - terminal UI for managing NetBird peers, routes, and settings
- caddy-netbird - Caddy plugin that embeds a NetBird client for proxying HTTP and TCP/UDP traffic through NetBird networks
Note: The main branch may be in an unstable or even broken state during development.
For stable versions, see releases.
Support acknowledgement
In November 2022, NetBird joined the StartUpSecure program sponsored by the Federal Ministry of Education and Research of the Federal Republic of Germany. Together with the CISPA Helmholtz Center for Information Security, NetBird brings security best practices and simplicity to private networking.
Acknowledgements
We build on open source technologies like WireGuard®, Pion ICE, and Rosenpass. We greatly appreciate the work these projects are doing, and we'd love it if you could support them too (e.g., by starring or contributing).
Legal
This repository is licensed under the BSD-3-Clause license, which applies to all parts of the repository except for the directories management/, signal/ and relay/. Those directories are licensed under the GNU Affero General Public License version 3.0 (AGPLv3). See the respective LICENSE files inside each directory.
WireGuard and the WireGuard logo are registered trademarks of Jason A. Donenfeld.