Brad Fitzpatrick
d4f2bb4cff
FreeBSD is a weak-host stack like Linux, so a LAN-adjacent machine can send a SYN for a node's Tailscale IP to the node's NIC and get the kernel's SYN-ACK from the peerapi port, confirming which tailnet identity that MAC address belongs to. Linux closes this with SO_BINDTODEVICE and macOS/iOS with IP_BOUND_IF, but FreeBSD has no per-socket interface bind (only IP_RECVIF and SO_SETFIB). Instead, treat FreeBSD like Android: when netstack is present, don't create a kernel-level peerapi listener at all and use the fake listener, since netstack already intercepts peerapi connections from peers in userspace and the kernel socket only ever served the local host. When netstack is compiled out (ts_omit_netstack), the kernel listener is the only way to serve peers, so keep it and log that it must be restricted with pf. Along the way, tailscaled's own pf source NAT rule on FreeBSD turned out to rewrite the source of such a SYN-ACK to the LAN IP and a random port, so a plain connect() from the LAN never completes. The SYN-ACK still leaks, though, so the natlab test now watches for SYN-ACKs on the attacker's NIC with tcpdump instead of checking for a completed handshake, and gains a FreeBSD variant. With the fix disabled, that variant fails on the leaked SYN-ACK from the peerapi port. Fixes #21419 Updates tailscale/corp#48248 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com> Change-Id: I0d2de4ebc9bae28450d500bd7b6ddbfa70f9052f
Tailscale
Private WireGuard® networks made easy
Overview
This repository contains the majority of Tailscale's open source code.
Notably, it includes the tailscaled daemon and
the tailscale CLI tool. The tailscaled daemon runs on Linux, Windows,
macOS, and to varying degrees
on FreeBSD and OpenBSD. The Tailscale iOS and Android apps use this repo's
code, but this repo doesn't contain the mobile GUI code.
Other Tailscale repos of note:
- the Android app is at https://github.com/tailscale/tailscale-android
- the Synology package is at https://github.com/tailscale/tailscale-synology
- the QNAP package is at https://github.com/tailscale/tailscale-qpkg
- the Chocolatey packaging is at https://github.com/tailscale/tailscale-chocolatey
For background on which parts of Tailscale are open source and why, see https://tailscale.com/opensource/.
Using
We serve packages for a variety of distros and platforms at https://pkgs.tailscale.com.
Other clients
The macOS, iOS, and Windows clients use the code in this repository but additionally include small GUI wrappers. The GUI wrappers on non-open source platforms are themselves not open source.
Building
We always require the latest Go release, currently Go 1.27. (While we build releases with our Go fork, its use is not required.)
go install tailscale.com/cmd/tailscale{,d}
If you're packaging Tailscale for distribution, use build_dist.sh
instead, to burn commit IDs and version info into the binaries:
./build_dist.sh tailscale.com/cmd/tailscale
./build_dist.sh tailscale.com/cmd/tailscaled
If your distro has conventions that preclude the use of
build_dist.sh, please do the equivalent of what it does in your
distro's way, so that bug reports contain useful version information.
Bugs
Please file any issues about this code or the hosted service on the issue tracker.
Contributing
PRs welcome! But please file bugs. Commit messages should reference bugs.
We require Developer Certificate of
Origin
Signed-off-by lines in commits.
See commit-messages.md (or skim git log) for our commit message style.
About Us
Tailscale is primarily developed by the people at https://github.com/orgs/tailscale/people. For other contributors, see:
- https://github.com/tailscale/tailscale/graphs/contributors
- https://github.com/tailscale/tailscale-android/graphs/contributors
Legal
WireGuard is a registered trademark of Jason A. Donenfeld.