diff options
| -rw-r--r-- | src/resolve/resolved-dns-answer.c | 21 | ||||
| -rw-r--r-- | src/resolve/resolved-dns-answer.h | 1 | ||||
| -rw-r--r-- | src/resolve/resolved-dns-cache.c | 25 |
3 files changed, 40 insertions, 7 deletions
diff --git a/src/resolve/resolved-dns-answer.c b/src/resolve/resolved-dns-answer.c index 13ad4ca6bd..89b9b0e1ea 100644 --- a/src/resolve/resolved-dns-answer.c +++ b/src/resolve/resolved-dns-answer.c @@ -149,6 +149,19 @@ int dns_answer_contains(DnsAnswer *a, DnsResourceKey *key) { return 0; } +int dns_answer_match_soa(DnsResourceKey *key, DnsResourceKey *soa) { + if (soa->class != DNS_CLASS_IN) + return 0; + + if (soa->type != DNS_TYPE_SOA) + return 0; + + if (!dns_name_endswith(DNS_RESOURCE_KEY_NAME(key), DNS_RESOURCE_KEY_NAME(soa))) + return 0; + + return 1; +} + int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **ret) { unsigned i; @@ -164,13 +177,7 @@ int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **r for (i = 0; i < a->n_rrs; i++) { - if (a->items[i].rr->key->class != DNS_CLASS_IN) - continue; - - if (a->items[i].rr->key->type != DNS_TYPE_SOA) - continue; - - if (dns_name_endswith(DNS_RESOURCE_KEY_NAME(key), DNS_RESOURCE_KEY_NAME(a->items[i].rr->key))) { + if (dns_answer_match_soa(key, a->items[i].rr->key)) { *ret = a->items[i].rr; return 1; } diff --git a/src/resolve/resolved-dns-answer.h b/src/resolve/resolved-dns-answer.h index 0757dd60d0..044d73b19c 100644 --- a/src/resolve/resolved-dns-answer.h +++ b/src/resolve/resolved-dns-answer.h @@ -49,6 +49,7 @@ DnsAnswer *dns_answer_unref(DnsAnswer *a); int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex); int dns_answer_add_soa(DnsAnswer *a, const char *name, uint32_t ttl); int dns_answer_contains(DnsAnswer *a, DnsResourceKey *key); +int dns_answer_match_soa(DnsResourceKey *key, DnsResourceKey *soa); int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **ret); DnsAnswer *dns_answer_merge(DnsAnswer *a, DnsAnswer *b); diff --git a/src/resolve/resolved-dns-cache.c b/src/resolve/resolved-dns-cache.c index 93b98f3727..ab13636bc1 100644 --- a/src/resolve/resolved-dns-cache.c +++ b/src/resolve/resolved-dns-cache.c @@ -474,6 +474,31 @@ 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, 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); if (r < 0) goto fail; |