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Diffstat (limited to 'src/resolve/resolved-dns-cache.c')
-rw-r--r--src/resolve/resolved-dns-cache.c64
1 files changed, 60 insertions, 4 deletions
diff --git a/src/resolve/resolved-dns-cache.c b/src/resolve/resolved-dns-cache.c
index 9ffaf4b19f..81ea1cafcb 100644
--- a/src/resolve/resolved-dns-cache.c
+++ b/src/resolve/resolved-dns-cache.c
@@ -95,14 +95,19 @@ void dns_cache_flush(DnsCache *c) {
c->by_expiry = prioq_free(c->by_expiry);
}
-static void dns_cache_remove(DnsCache *c, DnsResourceKey *key) {
+static bool dns_cache_remove(DnsCache *c, DnsResourceKey *key) {
DnsCacheItem *i;
+ bool exist = false;
assert(c);
assert(key);
- while ((i = hashmap_get(c->by_key, key)))
+ while ((i = hashmap_get(c->by_key, key))) {
dns_cache_item_remove_and_free(c, i);
+ exist = true;
+ }
+
+ return exist;
}
static void dns_cache_make_space(DnsCache *c, unsigned add) {
@@ -263,6 +268,7 @@ static int dns_cache_put_positive(
const union in_addr_union *owner_address) {
_cleanup_(dns_cache_item_freep) DnsCacheItem *i = NULL;
+ _cleanup_free_ char *key_str = NULL;
DnsCacheItem *existing;
int r;
@@ -272,7 +278,14 @@ static int dns_cache_put_positive(
/* New TTL is 0? Delete the entry... */
if (rr->ttl <= 0) {
- dns_cache_remove(c, rr->key);
+ if (dns_cache_remove(c, rr->key)) {
+ r = dns_resource_key_to_string(rr->key, &key_str);
+ if (r < 0)
+ return r;
+
+ log_debug("Removed zero TTL entry from cache: %s", key_str);
+ }
+
return 0;
}
@@ -311,6 +324,12 @@ static int dns_cache_put_positive(
if (r < 0)
return r;
+ r = dns_resource_key_to_string(i->key, &key_str);
+ if (r < 0)
+ return r;
+
+ log_debug("Added cache entry for %s", key_str);
+
i = NULL;
return 0;
}
@@ -325,6 +344,7 @@ static int dns_cache_put_negative(
const union in_addr_union *owner_address) {
_cleanup_(dns_cache_item_freep) DnsCacheItem *i = NULL;
+ _cleanup_free_ char *key_str = NULL;
int r;
assert(c);
@@ -337,8 +357,15 @@ static int dns_cache_put_negative(
return 0;
if (key->type == DNS_TYPE_ANY)
return 0;
- if (soa_ttl <= 0)
+ if (soa_ttl <= 0) {
+ r = dns_resource_key_to_string(key, &key_str);
+ if (r < 0)
+ return r;
+
+ log_debug("Ignored negative cache entry with zero SOA TTL: %s", key_str);
+
return 0;
+ }
if (!IN_SET(rcode, DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN))
return 0;
@@ -364,6 +391,12 @@ static int dns_cache_put_negative(
if (r < 0)
return r;
+ r = dns_resource_key_to_string(i->key, &key_str);
+ if (r < 0)
+ return r;
+
+ log_debug("Added %s cache entry for %s", i->type == DNS_CACHE_NODATA ? "NODATA" : "NXDOMAIN", key_str);
+
i = NULL;
return 0;
}
@@ -468,11 +501,19 @@ int dns_cache_lookup(DnsCache *c, DnsQuestion *q, int *rcode, DnsAnswer **ret) {
}
for (i = 0; i < q->n_keys; i++) {
+ _cleanup_free_ char *key_str = NULL;
DnsCacheItem *j;
if (q->keys[i]->type == DNS_TYPE_ANY ||
q->keys[i]->class == DNS_CLASS_ANY) {
/* If we have ANY lookups we simply refresh */
+
+ r = dns_resource_key_to_string(q->keys[i], &key_str);
+ if (r < 0)
+ return r;
+
+ log_debug("Ignoring cache for ANY lookup: %s", key_str);
+
*ret = NULL;
*rcode = 0;
return 0;
@@ -481,9 +522,24 @@ int dns_cache_lookup(DnsCache *c, DnsQuestion *q, int *rcode, DnsAnswer **ret) {
j = hashmap_get(c->by_key, q->keys[i]);
if (!j) {
/* If one question cannot be answered we need to refresh */
+
+ r = dns_resource_key_to_string(q->keys[i], &key_str);
+ if (r < 0)
+ return r;
+
+ log_debug("Cache miss for %s", key_str);
+
*ret = NULL;
*rcode = 0;
return 0;
+ } else {
+ r = dns_resource_key_to_string(j->key, &key_str);
+ if (r < 0)
+ return r;
+
+ log_debug("%s cache hit for %s",
+ j->type == DNS_CACHE_POSITIVE ? "Positive" :
+ (j->type == DNS_CACHE_NODATA ? "NODATA" : "NXDOMAIN"), key_str);
}
LIST_FOREACH(by_key, j, j) {