a68be19739
A connection to a Tailscale Service IP on a port the service does not serve was forwarded to the underlying host. `acceptTCP` fell through to the isTailscaleIP case (a VIP is in the Tailscale IP range), which rewrote the dial target to 127.0.0.1:<port> and forwardTCP'd the connection onto whatever unrelated listener happened to be on the host's loopback at that port. This is reachable through the service IP by any peer which was granted access only to the service (dst: svc:foo), so it exposes host ports the peer has no ACL access to via the machine's regular IP. This happens when there tailscaled has a Tun interface and the forward bits are set. In this commit, we added a guard in acceptTCP, before the isTailscaleIP case that RSTs connections to a VIP service IP on a port with no serve handler. Served ports return earlier via TCPHandlerForDst, so only unserved ports reach the guard. Layer 3 services are unaffected: their traffic is released to the host in injectInbound and never reaches acceptTCP. Fixes #20362 Signed-off-by: kevinliang10 <kevinliang@tailscale.com>
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 1.26. (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.