[PR #1975] [MERGED] Fix truncation for UDP #2730

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opened 2026-03-16 11:05:12 +03:00 by kerem · 0 comments

kerem commented

2026-03-16 11:05:12 +03:00

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📋 Pull Request Information

Original PR: https://github.com/hickory-dns/hickory-dns/pull/1975
Author: @nmittler
Created: 6/21/2023
Status: ✅ Merged
Merged: 6/27/2023
Merged by: @bluejekyll

Base: main ← Head: recv_buf

📝 Commits (1)

96681da Fix truncation for UDP

📊 Changes

9 files changed (+206 additions, -31 deletions)

View changed files

📝 crates/proto/src/serialize/binary/encoder.rs (+4 -4)
📝 crates/proto/src/udp/mod.rs (+4 -0)
📝 crates/proto/src/udp/udp_client_stream.rs (+15 -7)
📝 crates/proto/src/udp/udp_stream.rs (+2 -1)
📝 crates/server/src/authority/catalog.rs (+16 -15)
📝 crates/server/src/authority/message_response.rs (+5 -0)
📝 crates/server/src/server/response_handler.rs (+41 -3)
📝 crates/server/src/server/server_future.rs (+1 -1)
➕ tests/integration-tests/tests/truncation_tests.rs (+118 -0)

📄 Description

This fixes a couple of issues for UDP on both the client and server:

Previously, the UdpClientStream was using a fixed 2048 for the size of the receive buffer. This can cause problems on interfaces with a larger MTU. PR 1096 adjusted this value on the server side to 4096 (the maximum as recommended by RFC6891). This PR sets a constant that is shared by the UDP client and server. Additionally, the client uses EDNS in the request to further trim down the buffer size.
The Server previously was not setting a maximum for the BinEncoder, which defaults to u16::MAX (i.e. effectively no truncation for UDP). This PR sets an appropriate maximum for the BinEncoder based on the response EDNS and protocol being used.

Fixes: #1973

_{🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.}

## 📋 Pull Request Information **Original PR:** https://github.com/hickory-dns/hickory-dns/pull/1975 **Author:** [@nmittler](https://github.com/nmittler) **Created:** 6/21/2023 **Status:** ✅ Merged **Merged:** 6/27/2023 **Merged by:** [@bluejekyll](https://github.com/bluejekyll) **Base:** `main` ← **Head:** `recv_buf` --- ### 📝 Commits (1) - [`96681da`](https://github.com/hickory-dns/hickory-dns/commit/96681daf98aac469f8883aad61dcc9ec82703a91) Fix truncation for UDP ### 📊 Changes **9 files changed** (+206 additions, -31 deletions) <details> <summary>View changed files</summary> 📝 `crates/proto/src/serialize/binary/encoder.rs` (+4 -4) 📝 `crates/proto/src/udp/mod.rs` (+4 -0) 📝 `crates/proto/src/udp/udp_client_stream.rs` (+15 -7) 📝 `crates/proto/src/udp/udp_stream.rs` (+2 -1) 📝 `crates/server/src/authority/catalog.rs` (+16 -15) 📝 `crates/server/src/authority/message_response.rs` (+5 -0) 📝 `crates/server/src/server/response_handler.rs` (+41 -3) 📝 `crates/server/src/server/server_future.rs` (+1 -1) ➕ `tests/integration-tests/tests/truncation_tests.rs` (+118 -0) </details> ### 📄 Description This fixes a couple of issues for UDP on both the client and server: * Previously, the UdpClientStream was using a fixed `2048` for the size of the receive buffer. This can cause problems on interfaces with a larger MTU. [PR 1096](#1096) adjusted this value on the server side to 4096 (the maximum as recommended by RFC6891). This PR sets a constant that is shared by the UDP client and server. Additionally, the client uses EDNS in the request to further trim down the buffer size. * The Server previously was not setting a maximum for the `BinEncoder`, which defaults to `u16::MAX` (i.e. effectively no truncation for UDP). This PR sets an appropriate maximum for the `BinEncoder` based on the response EDNS and protocol being used. Fixes: #1973 --- <sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>