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Diffstat (limited to 'src/resolve/resolved-dns-cache.c')
-rw-r--r--src/resolve/resolved-dns-cache.c144
1 files changed, 116 insertions, 28 deletions
diff --git a/src/resolve/resolved-dns-cache.c b/src/resolve/resolved-dns-cache.c
index d963ce6e00..1774ae6cb8 100644
--- a/src/resolve/resolved-dns-cache.c
+++ b/src/resolve/resolved-dns-cache.c
@@ -46,6 +46,7 @@ struct DnsCacheItem {
usec_t until;
DnsCacheItemType type;
unsigned prioq_idx;
+ bool authenticated;
int owner_family;
union in_addr_union owner_address;
LIST_FIELDS(DnsCacheItem, by_key);
@@ -237,7 +238,7 @@ static DnsCacheItem* dns_cache_get(DnsCache *c, DnsResourceRecord *rr) {
return NULL;
}
-static void dns_cache_item_update_positive(DnsCache *c, DnsCacheItem *i, DnsResourceRecord *rr, usec_t timestamp) {
+static void dns_cache_item_update_positive(DnsCache *c, DnsCacheItem *i, DnsResourceRecord *rr, bool authenticated, usec_t timestamp) {
assert(c);
assert(i);
assert(rr);
@@ -257,6 +258,7 @@ static void dns_cache_item_update_positive(DnsCache *c, DnsCacheItem *i, DnsReso
dns_resource_key_unref(i->key);
i->key = dns_resource_key_ref(rr->key);
+ i->authenticated = authenticated;
i->until = timestamp + MIN(rr->ttl * USEC_PER_SEC, CACHE_TTL_MAX_USEC);
prioq_reshuffle(c->by_expiry, i, &i->prioq_idx);
@@ -265,6 +267,7 @@ static void dns_cache_item_update_positive(DnsCache *c, DnsCacheItem *i, DnsReso
static int dns_cache_put_positive(
DnsCache *c,
DnsResourceRecord *rr,
+ bool authenticated,
usec_t timestamp,
int owner_family,
const union in_addr_union *owner_address) {
@@ -300,7 +303,7 @@ static int dns_cache_put_positive(
/* Entry exists already? Update TTL and timestamp */
existing = dns_cache_get(c, rr);
if (existing) {
- dns_cache_item_update_positive(c, existing, rr, timestamp);
+ dns_cache_item_update_positive(c, existing, rr, authenticated, timestamp);
return 0;
}
@@ -322,6 +325,7 @@ static int dns_cache_put_positive(
i->prioq_idx = PRIOQ_IDX_NULL;
i->owner_family = owner_family;
i->owner_address = *owner_address;
+ i->authenticated = authenticated;
r = dns_cache_link_item(c, i);
if (r < 0)
@@ -341,6 +345,7 @@ static int dns_cache_put_negative(
DnsCache *c,
DnsResourceKey *key,
int rcode,
+ bool authenticated,
usec_t timestamp,
uint32_t soa_ttl,
int owner_family,
@@ -389,6 +394,7 @@ static int dns_cache_put_negative(
i->prioq_idx = PRIOQ_IDX_NULL;
i->owner_family = owner_family;
i->owner_address = *owner_address;
+ i->authenticated = authenticated;
r = dns_cache_link_item(c, i);
if (r < 0)
@@ -410,6 +416,7 @@ int dns_cache_put(
int rcode,
DnsAnswer *answer,
unsigned max_rrs,
+ bool authenticated,
usec_t timestamp,
int owner_family,
const union in_addr_union *owner_address) {
@@ -452,7 +459,12 @@ int dns_cache_put(
/* Second, add in positive entries for all contained RRs */
for (i = 0; i < MIN(max_rrs, answer->n_rrs); i++) {
- r = dns_cache_put_positive(c, answer->items[i].rr, timestamp, owner_family, owner_address);
+ DnsResourceRecord *rr = answer->items[i].rr;
+
+ if (rr->key->cache_flush)
+ dns_cache_remove(c, rr->key);
+
+ r = dns_cache_put_positive(c, rr, authenticated, timestamp, owner_family, owner_address);
if (r < 0)
goto fail;
}
@@ -496,13 +508,13 @@ int dns_cache_put(
if (!dns_answer_match_soa(canonical_key, soa->key))
continue;
- r = dns_cache_put_negative(c, canonical_key, rcode, timestamp, MIN(soa->soa.minimum, soa->ttl), owner_family, owner_address);
+ 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, timestamp, MIN(soa->soa.minimum, soa->ttl), owner_family, owner_address);
+ 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;
@@ -521,8 +533,7 @@ fail:
return r;
}
-static DnsCacheItem *dns_cache_get_by_key_follow_cname(DnsCache *c, DnsResourceKey *k) {
- _cleanup_(dns_resource_key_unrefp) DnsResourceKey *cname_key = NULL;
+static DnsCacheItem *dns_cache_get_by_key_follow_cname_dname_nsec(DnsCache *c, DnsResourceKey *k) {
DnsCacheItem *i;
const char *n;
int r;
@@ -534,32 +545,29 @@ static DnsCacheItem *dns_cache_get_by_key_follow_cname(DnsCache *c, DnsResourceK
* much, after all this is just a cache */
i = hashmap_get(c->by_key, k);
- if (i || k->type == DNS_TYPE_CNAME || k->type == DNS_TYPE_DNAME)
+ if (i || IN_SET(k->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME, DNS_TYPE_NSEC))
return i;
- /* Check if we have a CNAME record instead */
- cname_key = dns_resource_key_new_cname(k);
- if (!cname_key)
- return NULL;
+ n = DNS_RESOURCE_KEY_NAME(k);
- i = hashmap_get(c->by_key, cname_key);
+ /* 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)
+ return i;
+
+ /* Check if we have a CNAME record instead */
+ i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_CNAME, n));
if (i)
return i;
/* OK, let's look for cached DNAME records. */
- n = DNS_RESOURCE_KEY_NAME(k);
for (;;) {
- _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dname_key = NULL;
char label[DNS_LABEL_MAX];
if (isempty(n))
return NULL;
- dname_key = dns_resource_key_new(k->class, DNS_TYPE_DNAME, n);
- if (!dname_key)
- return NULL;
-
- i = hashmap_get(c->by_key, dname_key);
+ i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_DNAME, n));
if (i)
return i;
@@ -572,23 +580,26 @@ static DnsCacheItem *dns_cache_get_by_key_follow_cname(DnsCache *c, DnsResourceK
return NULL;
}
-int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, int *rcode, DnsAnswer **ret) {
+int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, int *rcode, DnsAnswer **ret, bool *authenticated) {
_cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
unsigned n = 0;
int r;
bool nxdomain = false;
_cleanup_free_ char *key_str = NULL;
- DnsCacheItem *j, *first;
+ DnsCacheItem *j, *first, *nsec = NULL;
+ bool have_authenticated = false, have_non_authenticated = false;
assert(c);
assert(key);
assert(rcode);
assert(ret);
+ assert(authenticated);
if (key->type == DNS_TYPE_ANY ||
key->class == DNS_CLASS_ANY) {
- /* If we have ANY lookups we simply refresh */
+ /* If we have ANY lookups we don't use the cache, so
+ * that the caller refreshes via the network. */
r = dns_resource_key_to_string(key, &key_str);
if (r < 0)
@@ -601,7 +612,7 @@ int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, int *rcode, DnsAnswer **r
return 0;
}
- first = dns_cache_get_by_key_follow_cname(c, key);
+ first = dns_cache_get_by_key_follow_cname_dname_nsec(c, key);
if (!first) {
/* If one question cannot be answered we need to refresh */
@@ -617,24 +628,49 @@ int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, int *rcode, DnsAnswer **r
}
LIST_FOREACH(by_key, j, first) {
- if (j->rr)
+ if (j->rr) {
+ if (j->rr->key->type == DNS_TYPE_NSEC)
+ nsec = j;
+
n++;
- else if (j->type == DNS_CACHE_NXDOMAIN)
+ } else if (j->type == DNS_CACHE_NXDOMAIN)
nxdomain = true;
+
+ if (j->authenticated)
+ have_authenticated = true;
+ else
+ have_non_authenticated = true;
}
r = dns_resource_key_to_string(key, &key_str);
if (r < 0)
return r;
+ if (nsec && key->type != DNS_TYPE_NSEC) {
+ log_debug("NSEC NODATA cache hit for %s", key_str);
+
+ /* We only found an NSEC record that matches our name.
+ * If it says the type doesn't exit report
+ * NODATA. Otherwise report a cache miss. */
+
+ *ret = NULL;
+ *rcode = DNS_RCODE_SUCCESS;
+ *authenticated = nsec->authenticated;
+
+ return !bitmap_isset(nsec->rr->nsec.types, key->type) &&
+ !bitmap_isset(nsec->rr->nsec.types, DNS_TYPE_CNAME) &&
+ !bitmap_isset(nsec->rr->nsec.types, DNS_TYPE_DNAME);
+ }
+
log_debug("%s cache hit for %s",
- nxdomain ? "NXDOMAIN" :
- n > 0 ? "Positive" : "NODATA",
+ n > 0 ? "Positive" :
+ nxdomain ? "NXDOMAIN" : "NODATA",
key_str);
if (n <= 0) {
*ret = NULL;
*rcode = nxdomain ? DNS_RCODE_NXDOMAIN : DNS_RCODE_SUCCESS;
+ *authenticated = have_authenticated && !have_non_authenticated;
return 1;
}
@@ -653,6 +689,7 @@ int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, int *rcode, DnsAnswer **r
*ret = answer;
*rcode = DNS_RCODE_SUCCESS;
+ *authenticated = have_authenticated && !have_non_authenticated;
answer = NULL;
return n;
@@ -694,6 +731,57 @@ int dns_cache_check_conflicts(DnsCache *cache, DnsResourceRecord *rr, int owner_
return 1;
}
+int dns_cache_export_shared_to_packet(DnsCache *cache, DnsPacket *p) {
+ unsigned ancount = 0;
+ Iterator iterator;
+ DnsCacheItem *i;
+ int r;
+
+ assert(cache);
+ assert(p);
+
+ HASHMAP_FOREACH(i, cache->by_key, iterator) {
+ DnsCacheItem *j;
+
+ LIST_FOREACH(by_key, j, i) {
+ _cleanup_free_ char *t = NULL;
+
+ if (!j->rr)
+ continue;
+
+ if (!dns_key_is_shared(j->rr->key))
+ continue;
+
+ r = dns_packet_append_rr(p, j->rr, NULL, NULL);
+ if (r == -EMSGSIZE && p->protocol == DNS_PROTOCOL_MDNS) {
+ /* For mDNS, if we're unable to stuff all known answers into the given packet,
+ * allocate a new one, push the RR into that one and link it to the current one.
+ */
+
+ DNS_PACKET_HEADER(p)->ancount = htobe16(ancount);
+ ancount = 0;
+
+ r = dns_packet_new_query(&p->more, p->protocol, 0, true);
+ if (r < 0)
+ return r;
+
+ /* continue with new packet */
+ p = p->more;
+ r = dns_packet_append_rr(p, j->rr, NULL, NULL);
+ }
+
+ if (r < 0)
+ return r;
+
+ ancount ++;
+ }
+ }
+
+ DNS_PACKET_HEADER(p)->ancount = htobe16(ancount);
+
+ return 0;
+}
+
void dns_cache_dump(DnsCache *cache, FILE *f) {
Iterator iterator;
DnsCacheItem *i;
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-12-15 03:24:09 +0000