tailscale/wgengine/magicsock/debugknobs.go, branch debug-testwrapper

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

wgengine/magicsock: add TS_DEBUG_NEVER_DIRECT_UDP debug knob (#17094)

2025-09-10T23:48:40Z

Updates tailscale/corp#30903 Signed-off-by: Jordan Whited

tailcfg,wgengine/magicsock: set peer relay CapVer (#16531)

2025-07-15T19:29:07Z

Updates tailscale/corp#27502 Updates tailscale/corp#30051 Signed-off-by: Jordan Whited

wgengine/magicsock: add envknob to toggle UDP relay feature (#16396)

2025-06-27T01:39:47Z

Updates tailscale/corp#27502 Signed-off-by: Jordan Whited

wgengine/magicsock: allow a CSV list for pretendpoint

2024-07-10T16:57:28Z

Load Balancers often have more than one ingress IP, so allowing us to add multiple means we can offer multiple options. Updates #12578 Change-Id: I4aa49a698d457627d2f7011796d665c67d4c7952 Signed-off-by: Lee Briggs

wgengine/magicsock: add debug envknob for injecting an endpoint

2024-07-08T14:59:40Z

For testing. Lee wants to play with 'AWS Global Accelerator Custom Routing with Amazon Elastic Kubernetes Service'. If this works well enough, we can promote it. Updates #12578 Change-Id: I5018347ed46c15c9709910717d27305d0aedf8f4 Signed-off-by: Brad Fitzpatrick

control/controlknobs,tailcfg,wgengine/magicsock: remove DRPO shutoff switch

2024-07-07T02:50:53Z

The DERP Return Path Optimization (DRPO) is over four years old (and on by default for over two) and we haven't had problems, so time to remove the emergency shutoff code (controlknob) which we've never used. The controlknobs are only meant for new features, to mitigate risk. But we don't want to keep them forever, as they kinda pollute the code. Updates #150 Change-Id: If021bc8fd1b51006d8bddd1ffab639bb1abb0ad1 Signed-off-by: Brad Fitzpatrick

all: cleanup unused code, part 2 (#10670)

2023-12-22T01:40:03Z

And enable U1000 check in staticcheck. Updates #cleanup Signed-off-by: Andrew Lytvynov

wgengine/magicsock: replace CanPMTUD() with ShouldPMTUD()

2023-09-21T11:17:12Z

Replace CanPMTUD() with ShouldPMTUD() to check if peer path MTU discovery should be enabled, in preparation for adding support for enabling/disabling peer MTU dynamically. Updated #311 Signed-off-by: Val

wgengine/magicsock: rename debugPMTUD() to debugEnablePMTUD()

2023-09-21T11:17:12Z

Make the debugknob variable name for enabling peer path MTU discovery match the env variable name. Updates #311 Signed-off-by: Val