1 files changed, 60 insertions, 0 deletions
diff --git a/src/shared/resolve-util.h b/src/shared/resolve-util.h
new file mode 100644
index 0000000..5883342
--- /dev/null
+++ b/src/shared/resolve-util.h
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include "conf-parser.h"
+#include "macro.h"
+
+typedef enum ResolveSupport ResolveSupport;
+typedef enum DnssecMode DnssecMode;
+typedef enum DnsOverTlsMode DnsOverTlsMode;
+
+enum ResolveSupport {
+        RESOLVE_SUPPORT_NO,
+        RESOLVE_SUPPORT_YES,
+        RESOLVE_SUPPORT_RESOLVE,
+        _RESOLVE_SUPPORT_MAX,
+        _RESOLVE_SUPPORT_INVALID = -1
+};
+
+enum DnssecMode {
+        /* No DNSSEC validation is done */
+        DNSSEC_NO,
+
+        /* Validate locally, if the server knows DO, but if not,
+         * don't. Don't trust the AD bit. If the server doesn't do
+         * DNSSEC properly, downgrade to non-DNSSEC operation. Of
+         * course, we then are vulnerable to a downgrade attack, but
+         * that's life and what is configured. */
+        DNSSEC_ALLOW_DOWNGRADE,
+
+        /* Insist on DNSSEC server support, and rather fail than downgrading. */
+        DNSSEC_YES,
+
+        _DNSSEC_MODE_MAX,
+        _DNSSEC_MODE_INVALID = -1
+};
+
+enum DnsOverTlsMode {
+        /* No connection is made for DNS-over-TLS */
+        DNS_OVER_TLS_NO,
+
+        /* Try to connect using DNS-over-TLS, but if connection fails,
+         * fallback to using an unencrypted connection */
+        DNS_OVER_TLS_OPPORTUNISTIC,
+
+        _DNS_OVER_TLS_MODE_MAX,
+        _DNS_OVER_TLS_MODE_INVALID = -1
+};
+
+CONFIG_PARSER_PROTOTYPE(config_parse_resolve_support);
+CONFIG_PARSER_PROTOTYPE(config_parse_dnssec_mode);
+CONFIG_PARSER_PROTOTYPE(config_parse_dns_over_tls_mode);
+
+const char* resolve_support_to_string(ResolveSupport p) _const_;
+ResolveSupport resolve_support_from_string(const char *s) _pure_;
+
+const char* dnssec_mode_to_string(DnssecMode p) _const_;
+DnssecMode dnssec_mode_from_string(const char *s) _pure_;
+
+const char* dns_over_tls_mode_to_string(DnsOverTlsMode p) _const_;
+DnsOverTlsMode dns_over_tls_mode_from_string(const char *s) _pure_;