diff options
| author | Tom Gundersen <teg@jklm.no> | 2015-12-03 19:53:35 +0100 |
|---|---|---|
| committer | Tom Gundersen <teg@jklm.no> | 2015-12-10 17:06:26 +0100 |
| commit | 71e136699ce8882d5749b794add7cbb9d282adaa (patch) | |
| tree | 2eac7547ed3f22a81bcbabc531d31d7c55a5cb87 | |
| parent | 5d27351f8546530cf779847b0b04b0172c09f9d0 (diff) | |
resolved: cache - don't cache NXDOMAIN by TYPE
An NXDOMAIN entry means there are no RRs of any type for a name,
so only cache by CLASS + NAME, rather than CLASS + NAME + TYPE.
| -rw-r--r-- | src/resolve/resolved-dns-cache.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/src/resolve/resolved-dns-cache.c b/src/resolve/resolved-dns-cache.c index 008277ab09..9ffbf1d1a6 100644 --- a/src/resolve/resolved-dns-cache.c +++ b/src/resolve/resolved-dns-cache.c @@ -364,6 +364,8 @@ static int dns_cache_put_negative( if (key->class == DNS_CLASS_ANY) return 0; if (key->type == DNS_TYPE_ANY) + /* This is particularly important to filter out as we use this as a + * pseudo-type for NXDOMAIN entries */ return 0; if (soa_ttl <= 0) { r = dns_resource_key_to_string(key, &key_str); @@ -389,13 +391,21 @@ static int dns_cache_put_negative( return -ENOMEM; i->type = rcode == DNS_RCODE_SUCCESS ? DNS_CACHE_NODATA : DNS_CACHE_NXDOMAIN; - i->key = dns_resource_key_ref(key); i->until = timestamp + MIN(soa_ttl * USEC_PER_SEC, CACHE_TTL_MAX_USEC); i->prioq_idx = PRIOQ_IDX_NULL; i->owner_family = owner_family; i->owner_address = *owner_address; i->authenticated = authenticated; + if (i->type == DNS_CACHE_NXDOMAIN) { + /* NXDOMAIN entries should apply equally to all types, so we use ANY as + * a pseudo type for this purpose here. */ + i->key = dns_resource_key_new(key->class, DNS_TYPE_ANY, DNS_RESOURCE_KEY_NAME(key)); + if (!i->key) + return -ENOMEM; + } else + i->key = dns_resource_key_ref(key); + r = dns_cache_link_item(c, i); if (r < 0) return r; @@ -534,6 +544,12 @@ static DnsCacheItem *dns_cache_get_by_key_follow_cname_dname_nsec(DnsCache *c, D n = DNS_RESOURCE_KEY_NAME(k); + /* Check if we have an NXDOMAIN cache item for the name, notice that we use + * the pseudo-type ANY for NXDOMAIN cache items. */ + i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_ANY, n)); + if (i && i->type == DNS_CACHE_NXDOMAIN) + return i; + /* Check if we have an NSEC record instead for the name. */ i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_NSEC, n)); if (i) |