diff options
| -rw-r--r-- | src/resolve/resolved-dns-transaction.c | 44 |
1 files changed, 37 insertions, 7 deletions
diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c index c0626626f2..ce320e9a97 100644 --- a/src/resolve/resolved-dns-transaction.c +++ b/src/resolve/resolved-dns-transaction.c @@ -1233,6 +1233,28 @@ int dns_transaction_go(DnsTransaction *t) { return 1; } +static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { + DnsTransaction *n; + Iterator i; + int r; + + assert(t); + assert(aux); + + /* Try to find cyclic dependencies between transaction objects */ + + if (t == aux) + return 1; + + SET_FOREACH(n, aux->notify_transactions, i) { + r = dns_transaction_find_cyclic(t, n); + if (r != 0) + return r; + } + + return r; +} + static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { DnsTransaction *aux; int r; @@ -1251,6 +1273,18 @@ static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResource *ret = aux; return 0; } + + r = dns_transaction_find_cyclic(t, aux); + if (r < 0) + return r; + if (r > 0) { + log_debug("Detected potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", + aux->id, + strna(dns_transaction_key_string(aux)), + t->id, + strna(dns_transaction_key_string(t))); + return -ELOOP; + } } r = set_ensure_allocated(&t->dnssec_transactions, NULL); @@ -1287,12 +1321,6 @@ static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey * assert(t); assert(key); - r = dns_resource_key_equal(t->key, key); - if (r < 0) - return r; - if (r > 0) /* Don't go in circles */ - return 0; - /* Try to get the data from the trust anchor */ r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); if (r < 0) @@ -1307,6 +1335,8 @@ static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey * /* This didn't work, ask for it via the network/cache then. */ r = dns_transaction_add_dnssec_transaction(t, key, &aux); + if (r == -ELOOP) /* This would result in a cyclic dependency */ + return 0; if (r < 0) return r; @@ -1316,7 +1346,7 @@ static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey * return r; } - return 0; + return 1; } static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |