resolved: partially revert 5eefe54

Quoting @teg:

"Contrary to what the comment said, we always verify redirect chains in
full, and cache all the CNAME records. There is therefore no need to
do extra negative caching along a CNAME chain."

This simply steals @teg's commit since we'll touch the SOA matching case
in a later patch, and rather want this bit gone, so that we don't have
to "fix" it, only to remove it later on.

1 files changed, 0 insertions, 25 deletions

diff --git a/src/resolve/resolved-dns-cache.c b/src/resolve/resolved-dns-cache.c
index 1774ae6cb8..f9769f5cda 100644
--- a/src/resolve/resolved-dns-cache.c
+++ b/src/resolve/resolved-dns-cache.c
@@ -489,31 +489,6 @@ int dns_cache_put(
         if (r == 0)
                 return 0;
 
-        /* Also, if the requested key is an alias, the negative response should
-           be cached for each name in the redirect chain. Any CNAME record in
-           the response is from the redirection chain, though only the final one
-           is guaranteed to be included. This means that we cannot verify the
-           chain and that we need to cache them all as it may be incomplete. */
-        for (i = 0; i < answer->n_rrs; i++) {
-                DnsResourceRecord *answer_rr = answer->items[i].rr;
-
-                if (answer_rr->key->type == DNS_TYPE_CNAME) {
-                        _cleanup_(dns_resource_key_unrefp) DnsResourceKey *canonical_key = NULL;
-
-                        canonical_key = dns_resource_key_new_redirect(key, answer_rr);
-                        if (!canonical_key)
-                                goto fail;
-
-                        /* Let's not add negative cache entries for records outside the current zone. */
-                        if (!dns_answer_match_soa(canonical_key, soa->key))
-                                continue;
-
-                        r = dns_cache_put_negative(c, canonical_key, rcode, authenticated, timestamp, MIN(soa->soa.minimum, soa->ttl), owner_family, owner_address);
-                        if (r < 0)
-                                goto fail;
-                }
-        }
-
         r = dns_cache_put_negative(c, key, rcode, authenticated, timestamp, MIN(soa->soa.minimum, soa->ttl), owner_family, owner_address);
         if (r < 0)
                 goto fail;