tailscale/control/controlknobs/controlknobs.go, branch bradfitz/rm_lazy_wg

wgengine, all: remove LazyWG, use wireguard-go callback API for on-demand peers

2026-04-25T01:53:13Z

Replace the UAPI text protocol-based wireguard configuration with wireguard-go's new direct callback API (SetPeerLookupFunc, SetPeerByIPPacketFunc, RemoveMatchingPeers, SetPrivateKey). Instead of computing a trimmed wireguard config ahead of time upon control plane updates and pushing it via UAPI, install callbacks so wireguard-go creates peers on demand when packets arrive. This removes all the LazyWG trimming machinery: idle peer tracking, activity maps, noteRecvActivity callbacks, the KeepFullWGConfig control knob, and the ts_omit_lazywg build tag. For incoming packets, PeerLookupFunc answers wireguard-go's questions about unknown public keys by looking up the peer in the full config. For outgoing packets, PeerByIPPacketFunc (installed from LocalBackend.lookupPeerByIP) maps destination IPs to node public keys using the existing nodeByAddr index. Updates tailscale/corp#12345 Change-Id: I4cba80979ac49a1231d00a01fdba5f0c2af95dd8 Signed-off-by: Brad Fitzpatrick

all: use Go 1.26 things, run most gofix modernizers

2026-03-06T21:32:03Z

I omitted a lot of the min/max modernizers because they didn't result in more clear code. Some of it's older "for x := range 123". Also: errors.AsType, any, fmt.Appendf, etc. Updates #18682 Change-Id: I83a451577f33877f962766a5b65ce86f7696471c Signed-off-by: Brad Fitzpatrick

net/dns: make MagicDNS IPv6 registration opt-out now, not opt-in

2026-02-17T17:29:12Z

This adds a new ControlKnob to make MagicDNS IPv6 registration (telling systemd/etc) opt-out rather than opt-in. Updates #15404 Change-Id: If008e1cb046b792c6aff7bb1d7c58638f7d650b1 Signed-off-by: Brad Fitzpatrick

control/controlknobs,net/dns,tailcfg: add a control knob that disables hosts file updates on Windows

2026-02-13T17:59:37Z

In the absence of a better mechanism, writing unqualified hostnames to the hosts file may be required for MagicDNS to work on some Windows environments, such as domain-joined machines. It can also improve MagicDNS performance on non-domain joined devices when we are not the device's primary DNS resolver. At the same time, updating the hosts file can be slow and expensive, especially when it already contains many entries, as was previously reported in #14327. It may also have negative side effects, such as interfering with the system's DNS resolution policies. Additionally, to fix #18712, we had to extend hosts file usage to domain-joined machines when we are not the primary DNS resolver. For the reasons above, this change may introduce risk. To allow customers to disable hosts file updates remotely without disabling MagicDNS entirely, whether on domain-joined machines or not, this PR introduces the `disable-hosts-file-updates` node attribute. Updates #18712 Updates #14327 Signed-off-by: Nick Khyl

all: remove AUTHORS file and references to it

2026-01-23T23:49:45Z

This file was never truly necessary and has never actually been used in the history of Tailscale's open source releases. A Brief History of AUTHORS files --- The AUTHORS file was a pattern developed at Google, originally for Chromium, then adopted by Go and a bunch of other projects. The problem was that Chromium originally had a copyright line only recognizing Google as the copyright holder. Because Google (and most open source projects) do not require copyright assignemnt for contributions, each contributor maintains their copyright. Some large corporate contributors then tried to add their own name to the copyright line in the LICENSE file or in file headers. This quickly becomes unwieldy, and puts a tremendous burden on anyone building on top of Chromium, since the license requires that they keep all copyright lines intact. The compromise was to create an AUTHORS file that would list all of the copyright holders. The LICENSE file and source file headers would then include that list by reference, listing the copyright holder as "The Chromium Authors". This also become cumbersome to simply keep the file up to date with a high rate of new contributors. Plus it's not always obvious who the copyright holder is. Sometimes it is the individual making the contribution, but many times it may be their employer. There is no way for the proejct maintainer to know. Eventually, Google changed their policy to no longer recommend trying to keep the AUTHORS file up to date proactively, and instead to only add to it when requested: https://opensource.google/docs/releasing/authors. They are also clear that: > Adding contributors to the AUTHORS file is entirely within the > project's discretion and has no implications for copyright ownership. It was primarily added to appease a small number of large contributors that insisted that they be recognized as copyright holders (which was entirely their right to do). But it's not truly necessary, and not even the most accurate way of identifying contributors and/or copyright holders. In practice, we've never added anyone to our AUTHORS file. It only lists Tailscale, so it's not really serving any purpose. It also causes confusion because Tailscalars put the "Tailscale Inc & AUTHORS" header in other open source repos which don't actually have an AUTHORS file, so it's ambiguous what that means. Instead, we just acknowledge that the contributors to Tailscale (whoever they are) are copyright holders for their individual contributions. We also have the benefit of using the DCO (developercertificate.org) which provides some additional certification of their right to make the contribution. The source file changes were purely mechanical with: git ls-files | xargs sed -i -e 's/\(Tailscale Inc &\) AUTHORS/\1 contributors/g' Updates #cleanup Change-Id: Ia101a4a3005adb9118051b3416f5a64a4a45987d Signed-off-by: Will Norris

control, ipn, tailcfg: enable seamless key renewal by default

2025-09-18T08:59:46Z

Previously, seamless key renewal was an opt-in feature. Customers had to set a `seamless-key-renewal` node attribute in their policy file. This patch enables seamless key renewal by default for all clients. It includes a `disable-seamless-key-renewal` node attribute we can set in Control, so we can manage the rollout and disable the feature for clients with known bugs. This new attribute makes the feature opt-out. Updates tailscale/corp#31479 Signed-off-by: Alex Chan

control/controlknobs,tailcfg,wgengine/magicsock: deprecate NodeAttrDisableMagicSockCryptoRouting (#16818)

2025-08-11T16:04:03Z

Peer Relay is dependent on crypto routing, therefore crypto routing is now mandatory. Updates tailscale/corp#20732 Updates tailscale/corp#31083 Signed-off-by: Jordan Whited

control/controlknobs: make Knobs.AsDebugJSON automatic, not require maintenance

2025-01-26T18:49:11Z

The AsDebugJSON method (used only for a LocalAPI debug call) always needed to be updated whenever a new controlknob was added. We had a test for it, which was nice, but it was a tedious step we don't need to do. Use reflect instead. Updates #14788 Change-Id: If59cd776920f3ce7c748f86ed2eddd9323039a0b Signed-off-by: Brad Fitzpatrick

control/controlclient: skip SetControlClientStatus when queue has newer results later

2025-01-25T00:16:22Z

Updates #1909 Updates #12542 Updates tailscale/corp#26058 Change-Id: I3033d235ca49f9739fdf3deaf603eea4ec3e407e Signed-off-by: Brad Fitzpatrick

health: introduce captive-portal-detected Warnable (#12707)

2024-07-26T18:25:55Z

Updates tailscale/tailscale#1634 This PR introduces a new `captive-portal-detected` Warnable which is set to an unhealthy state whenever a captive portal is detected on the local network, preventing Tailscale from connecting. ipn/ipnlocal: fix captive portal loop shutdown Change-Id: I7cafdbce68463a16260091bcec1741501a070c95 net/captivedetection: fix mutex misuse ipn/ipnlocal: ensure that we don't fail to start the timer Change-Id: I3e43fb19264d793e8707c5031c0898e48e3e7465 Signed-off-by: Andrew Dunham Signed-off-by: Andrea Gottardo