picnoir/Systemd
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

resolved: check SOA authentication state when negative caching

Browse source 
We should never use the TTL of an unauthenticated SOA to cache an
authenticated RR.
This commit is contained in:
Lennart Poettering 2015-12-18 19:12:48 +01:00
parent 1069048089
commit fd009cd80e
3 changed files with 12 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
src/resolve/resolved-dns-answer.c
View file

@ -302,8 +302,9 @@ int dns_answer_contains_nsec_or_nsec3(DnsAnswer *a) {
return false;
}
int dns_answer_find_soa(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret) {
int dns_answer_find_soa(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *flags) {
DnsResourceRecord *rr;
DnsAnswerFlags rr_flags;
int r;
assert(key);
@ -312,13 +313,15 @@ int dns_answer_find_soa(DnsAnswer *a, const DnsResourceKey *key, DnsResourceReco
if (key->type == DNS_TYPE_SOA)
return 0;
DNS_ANSWER_FOREACH(rr, a) {
DNS_ANSWER_FOREACH_FLAGS(rr, rr_flags, a) {
r = dns_resource_key_match_soa(key, rr->key);
if (r < 0)
return r;
if (r > 0) {
if (ret)
*ret = rr;
if (flags)
*flags = rr_flags;
return 1;
}
}

2
src/resolve/resolved-dns-answer.h
View file

@ -64,7 +64,7 @@ int dns_answer_contains_rr(DnsAnswer *a, DnsResourceRecord *rr, DnsAnswerFlags *
int dns_answer_contains_key(DnsAnswer *a, const DnsResourceKey *key, DnsAnswerFlags *combined_flags);
int dns_answer_contains_nsec_or_nsec3(DnsAnswer *a);
int dns_answer_find_soa(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret);
int dns_answer_find_soa(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *flags);
int dns_answer_find_cname_or_dname(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *flags);
int dns_answer_merge(DnsAnswer *a, DnsAnswer *b, DnsAnswer **ret);

7
src/resolve/resolved-dns-cache.c
View file

@ -529,12 +529,17 @@ int dns_cache_put(
* matching SOA record in the packet is used to to enable
* negative caching. */
r = dns_answer_find_soa(answer, key, &soa);
r = dns_answer_find_soa(answer, key, &soa, &flags);
if (r < 0)
goto fail;
if (r == 0)
return 0;
/* Refuse using the SOA data if it is unsigned, but the key is
* signed */
if (authenticated && (flags & DNS_ANSWER_AUTHENTICATED) == 0)
return 0;
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;