From 0a18f3e59f887f27431759443374cd559fce729d Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 21 Aug 2015 22:47:06 +0200
Subject: resolved: add reference to negative caching RFC

---
 src/resolve/resolved-dns-cache.c | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'src/resolve')

diff --git a/src/resolve/resolved-dns-cache.c b/src/resolve/resolved-dns-cache.c
index eb51b4b895..751e961351 100644
--- a/src/resolve/resolved-dns-cache.c
+++ b/src/resolve/resolved-dns-cache.c
@@ -458,6 +458,10 @@ int dns_cache_put(
                 if (r > 0)
                         continue;
 
+                /* See https://tools.ietf.org/html/rfc2308, which
+                 * say that a matching SOA record in the packet
+                 * is used to to enable negative caching. */
+
                 r = dns_answer_find_soa(answer, q->keys[i], &soa);
                 if (r < 0)
                         goto fail;
-- 
cgit v1.2.3-54-g00ecf