[PR #2339] [MERGED] CNAME resolution support for the recursor. #2965

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opened 2026-03-16 11:17:57 +03:00 by kerem · 0 comments

kerem commented

2026-03-16 11:17:57 +03:00

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📋 Pull Request Information

Original PR: https://github.com/hickory-dns/hickory-dns/pull/2339
Author: @marcus0x62
Created: 8/4/2024
Status: ✅ Merged
Merged: 9/14/2024
Merged by: @marcus0x62

Base: main ← Head: recursor_cname

📝 Commits (4)

47ddecb Add extend_records method to Lookup implementation to allow the recursor CNAME mechanism
0353ba8 Preserve original query type in cache lookup
89d2083 CNAME lookup logic for the recursor
ee85315 Tests for the recursor CNAME implementation

📊 Changes

11 files changed (+492 additions, -18 deletions)

View changed files

📝 crates/recursor/src/recursor.rs (+19 -2)
📝 crates/recursor/src/recursor_dns_handle.rs (+118 -7)
📝 crates/resolver/src/dns_lru.rs (+12 -9)
📝 crates/resolver/src/lookup.rs (+8 -0)
📝 crates/server/src/store/recursor/authority.rs (+1 -0)
📝 crates/server/src/store/recursor/config.rs (+8 -0)
📝 tests/e2e-tests/src/lib.rs (+1 -0)
➕ tests/e2e-tests/src/recursor.rs (+1 -0)
➕ tests/e2e-tests/src/recursor/cname.rs (+1 -0)
➕ tests/e2e-tests/src/recursor/cname/scenarios.rs (+322 -0)
📝 tests/test-data/test_configs/example_recursor.toml (+1 -0)

📄 Description

This PR adds support for CNAME resolution to the recursor, along with a set of related changes:

A new extend_records method in crates/resolver/src/lookup.rs to facilitate appending the resolved CNAMES to the original Lookup result.
A change to the DNS LRU insert_records function to use the original query type when inserting a CNAME record, to facilitate later retrieval of the record.
Core CNAME lookup logic for the recursor and a configurable recursion depth limit (default: 12 nested lookups) to prevent lookup loops
CNAME-related tests for single CNAME queries, CNAME chain queries, and the recursion depth limit.

_{🔄 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/2339 **Author:** [@marcus0x62](https://github.com/marcus0x62) **Created:** 8/4/2024 **Status:** ✅ Merged **Merged:** 9/14/2024 **Merged by:** [@marcus0x62](https://github.com/marcus0x62) **Base:** `main` ← **Head:** `recursor_cname` --- ### 📝 Commits (4) - [`47ddecb`](https://github.com/hickory-dns/hickory-dns/commit/47ddecbebdd2eac9b9d0dfeae5183febf2f0e57b) Add extend_records method to Lookup implementation to allow the recursor CNAME mechanism - [`0353ba8`](https://github.com/hickory-dns/hickory-dns/commit/0353ba843dbe839c1c252d198f6abdf0b1ce6643) Preserve original query type in cache lookup - [`89d2083`](https://github.com/hickory-dns/hickory-dns/commit/89d2083aee6e27d257eefb09e8716d14678dfa44) CNAME lookup logic for the recursor - [`ee85315`](https://github.com/hickory-dns/hickory-dns/commit/ee85315f854112aeb31f6932863c54f6b57a8793) Tests for the recursor CNAME implementation ### 📊 Changes **11 files changed** (+492 additions, -18 deletions) <details> <summary>View changed files</summary> 📝 `crates/recursor/src/recursor.rs` (+19 -2) 📝 `crates/recursor/src/recursor_dns_handle.rs` (+118 -7) 📝 `crates/resolver/src/dns_lru.rs` (+12 -9) 📝 `crates/resolver/src/lookup.rs` (+8 -0) 📝 `crates/server/src/store/recursor/authority.rs` (+1 -0) 📝 `crates/server/src/store/recursor/config.rs` (+8 -0) 📝 `tests/e2e-tests/src/lib.rs` (+1 -0) ➕ `tests/e2e-tests/src/recursor.rs` (+1 -0) ➕ `tests/e2e-tests/src/recursor/cname.rs` (+1 -0) ➕ `tests/e2e-tests/src/recursor/cname/scenarios.rs` (+322 -0) 📝 `tests/test-data/test_configs/example_recursor.toml` (+1 -0) </details> ### 📄 Description This PR adds support for CNAME resolution to the recursor, along with a set of related changes: 1. A new extend_records method in [crates/resolver/src/lookup.rs](https://github.com/hickory-dns/hickory-dns/blob/f7ef5cdf08730ecb04ba0947d9bbc309400c9b4b/crates/resolver/src/lookup.rs#L144) to facilitate appending the resolved CNAMES to the original Lookup result. 2. A [change](https://github.com/marcus0x62/hickory-dns/blob/77bdf979cceba089d04fe718abe7db73ff49c074/crates/resolver/src/dns_lru.rs#L279) to the DNS LRU insert_records function to use the original query type when inserting a CNAME record, to facilitate later retrieval of the record. 3. Core CNAME lookup logic for the recursor and a configurable recursion depth limit (default: 12 nested lookups) to prevent lookup loops 4. CNAME-related tests for single CNAME queries, CNAME chain queries, and the recursion depth limit. --- <sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>