resolved: move DNS class utilities to dns-type.c and add more helpers

Let's make DNS class helpers more like DNS type helpers, let's move them
from resolved-dns-rr.[ch] into dns-type.[ch].

This also adds two new calls dns_class_is_pseudo() and
dns_class_is_valid_rr() which operate similar to dns_type_is_pseudo()
and dns_type_is_valid_rr() but for classes instead of types.

This should hopefully make handling of DNS classes and DNS types more
alike.

1 files changed, 14 insertions, 0 deletions

diff --git a/src/resolve/dns-type.h b/src/resolve/dns-type.h
index 038a0d0e54..deb89e9b7e 100644
--- a/src/resolve/dns-type.h
+++ b/src/resolve/dns-type.h
@@ -122,3 +122,17 @@ enum {
 assert_cc(DNS_TYPE_SSHFP == 44);
 assert_cc(DNS_TYPE_TLSA == 52);
 assert_cc(DNS_TYPE_ANY == 255);
+
+/* DNS record classes, see RFC 1035 */
+enum {
+        DNS_CLASS_IN   = 0x01,
+        DNS_CLASS_ANY  = 0xFF,
+        _DNS_CLASS_MAX,
+        _DNS_CLASS_INVALID = -1
+};
+
+bool dns_class_is_pseudo(uint16_t class);
+bool dns_class_is_valid_rr(uint16_t class);
+
+const char *dns_class_to_string(uint16_t type);
+int dns_class_from_string(const char *name);