cmd/tailscaled, tsnet: don't return an interface containing a nil pointer #10752
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…nter
This tripped me up when I was testing something and wrote:
if conn != nil {
conn.Close()
}
In netstack mode, when an error occurred we were getting a non-nil error
and a non-nil interface that contained a nil pointer. Instead, just
return a nil interface value.
Updates #cleanup
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Id9ef3dd24529e0e8c53adc60ed914c31fbb10cc4
icio
approved these changes
Jan 5, 2024
| @@ -511,7 +511,13 @@ func getLocalBackend(ctx context.Context, logf logger.Logf, logID logid.PublicID | |||
| return ok | |||
| } | |||
| dialer.NetstackDialTCP = func(ctx context.Context, dst netip.AddrPort) (net.Conn, error) { | |||
| return ns.DialContextTCP(ctx, dst) | |||
| // Note: don't just return ns.DialContextTCP or we'll | |||
| // return an interface containing a nil pointer. | |||
There was a problem hiding this comment.
The comments are good but it might be worth writing a little test to ensure there's no regressions of this behaviour.
There was a problem hiding this comment.
I tried that, but it's super annoying to test this since it's in the main package, and requires a running Tailscale backend to even get this far 😵💫
creachadair
approved these changes
Jan 5, 2024
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This tripped me up when I was testing something and wrote:
In netstack mode, when an error occurred we were getting a non-nil error and a non-nil interface that contained a nil pointer. Instead, just return a nil interface value.
Updates #cleanup
Change-Id: Id9ef3dd24529e0e8c53adc60ed914c31fbb10cc4