Riccardo Manfrin
5433e92183
* [client] Pass the home relay client into isForeignServer isForeignServer read m.relayClient directly, so it was only safe while the caller held relayClientMu, and that dependency was invisible at the call site. Taking the client as a parameter makes the requirement explicit and lets a caller narrow the window it holds the lock for. Pure refactor, no behavior change: the single caller passes m.relayClient while still holding the read lock. * [client] Release the relay client lock before dialing a foreign server OpenConn held relayClientMu for its whole body, dial included. Dialing a foreign relay takes as long as that server's connect timeout, and onServerDisconnected needs the same mutex in write mode; a pending writer also blocks later readers, so a single unreachable relay stalled every relay operation on the node for the duration of the dial. On a routing peer this stalled the disconnect handling of an unrelated relay for a full dial timeout. By the time the eviction ran, the track had already been rebuilt, so it dropped a working client and the next OpenConn built a duplicate connection to a server the peer was already connected to. Read the home client under the lock, then release it and dial unlocked. * [client] Keep a reconnected foreign relay client on a late disconnect notice evictForeignRelay deleted the track by server address without checking which client the entry held. The disconnect notice is delivered on its own goroutine and carries only the address, so it can arrive after the track has been rebuilt: the eviction then dropped a live client, and the next OpenConn built a second connection to a server the peer was already connected to. The relay answers a duplicate peer ID by closing the existing connection, which tears down every relayed channel on it, including the peers whose active path it is. Skip the eviction when the stored client is still connected. * [client] Drop the comments added with the previous commits Comment-only change, no behavior change. * [client] Cover the foreign relay stall and the late disconnect notice Two regression tests, both failing on the unfixed code: TestOpenConn_DoesNotHoldRelayClientLockAcrossDial dials a listener that accepts and never answers, then calls onServerDisconnected and fails if it does not return. On the unfixed code the writer waits out the whole dial. TestEvictForeignRelay_KeepsConnectedClient opens a real connection to a second relay and then replays a disconnect notice for that address. On the unfixed code the live client is dropped from the map. Both reuse the existing stallingRelayListener and relay server helpers. * [client] Keep a foreign relay track whose dial is still in progress openConnVia publishes the track before dialing and fills relayClient only once the dial finishes, so the readiness guard did not cover the dial-in-progress window: a disconnect notice arriving there deleted a track whose client was about to connect. That client then became unreachable through the map, so cleanUpUnusedRelays could not close it either, and the next OpenConn dialed a duplicate the relay answers by closing the first - the churn this branch is meant to remove. Skip the eviction while relayClient is still nil, the same signal cleanUpUnusedRelays already uses to leave an in-flight dial alone. Reported by cubic on PR #8098.
Start using NetBird at netbird.io
See Documentation
Join our Slack channel or our Community forum
🚀 We are hiring! Join us at https://netbird.io/careers
🤖 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.
Reporting bugs and requesting features
NetBird uses a discussion-first workflow. Bug reports and feature requests start in Discussions, not as issues.
| What you want to do | Where to go |
|---|---|
| Report a bug, regression, or unexpected behavior | Issue Triage |
| Request a feature or share an idea | Ideas & Feature Requests |
| Ask about setup, configuration, or self-hosting | Q&A / Support |
| Report a security vulnerability | Security policy, never a public thread |
Our team and maintainers triage discussions, ask follow-up questions, check for duplicates, and reproduce bugs. Validated reports are promoted to issues. This keeps the issue tracker a clear answer to one question: what is the team working on.
Please search existing discussions and issues first, including closed ones. If something similar already exists, upvote it and add your details there instead of opening a duplicate.
For bug reports, include your NetBird version, operating system, deployment type (Cloud, self-hosted, Kubernetes, or Docker), reproduction steps, expected and actual behavior, and a debug bundle where relevant:
netbird version
netbird status -d -A
netbird debug for 1m -A -S -U
-U uploads the bundle and prints a file key you can paste instead of attaching the archive.
-A anonymizes the output, which matters on a public thread. It masks most identifying details
but is not full redaction, so read the bundle before posting it. Two levels are available:
| Level | How to select | What it masks |
|---|---|---|
default |
-A / --anonymize |
Public IP addresses, IPv6 ULA addresses, MAC addresses, and domains other than netbird.io, netbird.cloud, netbird.selfhosted, and netbird.stage. IPv4 private, CGNAT, and link-local ranges are kept |
strict |
--anonymize-level strict (implies -A) |
The above, plus IPv4 private, CGNAT, and link-local ranges, peer names in front of netbird.cloud, netbird.selfhosted, and netbird.stage, and WireGuard public keys. Labels under netbird.io are kept, since it only hosts infrastructure |
See collecting a debug bundle and the CLI reference for details.
See How to use Discussions, Issues, and Pull Requests for the full workflow, or SUPPORT.md for a shorter version.
Contributing
Contributions are welcome. Read CONTRIBUTING.md first. NetBird works ticket first, anything that changes behavior needs an issue the team has agreed on before you open a pull request.
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.