This prevents running more than one recursive resolution for the same
hostname in parallel, which can use excessive amounts of CPU when called
in a tight loop. Additionally, add tests that hit the network (when
run with a flag) to test the lookup behaviour.
Updates tailscale/corp#15261
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I39351e1d2a8782dd4c52cb04b3bd982eb651c81e
Redoes the approach from #5550 and #7539 to explicitly pass in the logf
function, instead of having global state that can be overridden.
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
This updates all source files to use a new standard header for copyright
and license declaration. Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.
This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.
Updates #6865
Signed-off-by: Will Norris <will@tailscale.com>
This is especially helpful as we launch newer DERPs over time, and older
clients have progressively out-of-date static DERP maps baked in. After
this, as long as the client has successfully connected once, it'll cache
the most recent DERP map it knows about.
Resolves an in-code comment from @bradfitz
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Move derpmap.Prod to a static JSON file (go:generate'd) instead,
to make its role explicit. And add a TODO about making dnsfallback
use an update-over-time DERP map file instead of a baked-in one.
Updates #1264
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
