Commit Graph

6 Commits (0f3a292ebde93c9508f230e1b0b49f22a80b4c62)

Author SHA1 Message Date
Andrew Dunham e33bc64cff net/dnsfallback: add singleflight to recursive resolver
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
1 year ago
Mihai Parparita 9a655a1d58 net/dnsfallback: more explicitly pass through logf function
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>
2 years ago
Will Norris 71029cea2d all: update copyright and license headers
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>
2 years ago
Andrew Dunham f52a659076
net/dnsfallback: allow setting log function (#5550)
This broke a test in corp that enforces we don't use the log package.

Signed-off-by: Andrew Dunham <andrew@tailscale.com>
2 years ago
Andrew Dunham b8596f2a2f
net/dnsfallback: cache most recent DERP map on disk (#5545)
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clients have progressively out-of-date static DERP maps baked in.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>
2 years ago
Brad Fitzpatrick 10d7c2583c net/dnsfallback: don't depend on derpmap.Prod
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>
3 years ago