initialize the MTU discoverer when processing the transport parameters #4514
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
marten-seemann
commented
May 14, 2024
| @@ -153,7 +153,7 @@ type connection struct { | |||
| unpacker unpacker | |||
| frameParser wire.FrameParser | |||
| packer packer | |||
| mtuDiscoverer mtuDiscoverer // initialized when the handshake completes | |||
| mtuDiscoverer mtuDiscoverer // initialized when the transport parameters are received | |||
There was a problem hiding this comment.
Note that the original comment here was incorrect: We used to initialize the mtuDiscoverer with the connection, not on handshake completion.
On the client side, we always use the configured packet size. This comes with the risk of failing the handshake if the path doesn't support this MTU. If the server sends a max_udp_payload_size that's smaller than this size, we can safely ignore this: Obviously, the server still processed the (fully padded) Initial packet, despite claiming that it wouldn't do so. On the server side, there's no downside to using 1200 bytes until we received the client's transport parameters: * If the first packet didn't contain the entire ClientHello, all we can do is ACK that packet. We don't need a lot of bytes for that. * If it did, we will have processed the transport parameters and initialized the MTU discoverer.
marten-seemann
force-pushed
the
initialize-mtu-discoverer-on-tp
branch
from
84a3aea
to
b4a6d66
Compare
Codecov ReportAttention: Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## master #4514 +/- ##
==========================================
- Coverage 85.16% 85.15% -0.01%
==========================================
Files 154 154
Lines 14768 14782 +14
==========================================
+ Hits 12577 12587 +10
- Misses 1686 1688 +2
- Partials 505 507 +2 ☔ View full report in Codecov by Sentry. |
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.
On the client side, we always use the configured packet size. This comes with the risk of failing the handshake if the path doesn't support this MTU. If the server sends a max_udp_payload_size that's smaller than this size, we can safely ignore this: Obviously, the server still processed the (fully padded) Initial packet, despite claiming that it wouldn't do so.
On the server side, there's no downside to using 1200 bytes until we received the client's transport parameters: