Add missing getdns constants

- Constants are pulled from `getdns/src/getdns/getdns.h.in` and `getdns/src/getdns/getdns_extra.h.in`.
- Text strings have not been included yet.
- Version strings etcetera have been skipped for now.
- The rest has been added blindly.
- This should reduce magic number usage and facilitate return code checks.
- Future versions might (reintroduce) javascript level constant exports using ES6 modules.

This relates to getdnsapi#18, but is not a complete solution. Functions, and possibly other things, still need to be checked.

Author: joelpurra

src/GNConstants.cpp

@@ -44,6 +44,8 @@ void GNConstants::Init(Local<Object> target) {
     SetConstant("RETURN_GOOD",GETDNS_RETURN_GOOD,exports);
     SetConstant("RETURN_GENERIC_ERROR",GETDNS_RETURN_GENERIC_ERROR,exports);
     SetConstant("RETURN_BAD_DOMAIN_NAME",GETDNS_RETURN_BAD_DOMAIN_NAME,exports);
+    SetConstant("RETURN_BAD_CONTEXT",GETDNS_RETURN_BAD_CONTEXT,exports);
+    SetConstant("RETURN_CONTEXT_UPDATE_FAIL",GETDNS_RETURN_CONTEXT_UPDATE_FAIL,exports);
     SetConstant("RETURN_UNKNOWN_TRANSACTION",GETDNS_RETURN_UNKNOWN_TRANSACTION,exports);
     SetConstant("RETURN_NO_SUCH_LIST_ITEM",GETDNS_RETURN_NO_SUCH_LIST_ITEM,exports);
     SetConstant("RETURN_NO_SUCH_DICT_NAME",GETDNS_RETURN_NO_SUCH_DICT_NAME,exports);
@@ -54,6 +56,7 @@ void GNConstants::Init(Local<Object> target) {
     SetConstant("RETURN_MEMORY_ERROR",GETDNS_RETURN_MEMORY_ERROR,exports);
     SetConstant("RETURN_INVALID_PARAMETER",GETDNS_RETURN_INVALID_PARAMETER,exports);
     SetConstant("RETURN_NOT_IMPLEMENTED",GETDNS_RETURN_NOT_IMPLEMENTED,exports);
+    SetConstant("RETURN_NEED_MORE_SPACE",GETDNS_RETURN_NEED_MORE_SPACE,exports);
     SetConstant("DNSSEC_SECURE",GETDNS_DNSSEC_SECURE,exports);
     SetConstant("DNSSEC_BOGUS",GETDNS_DNSSEC_BOGUS,exports);
     SetConstant("DNSSEC_INDETERMINATE",GETDNS_DNSSEC_INDETERMINATE,exports);
@@ -74,12 +77,34 @@ void GNConstants::Init(Local<Object> target) {
     SetConstant("TRANSPORT_TCP_ONLY_KEEP_CONNECTIONS_OPEN",GETDNS_TRANSPORT_TCP_ONLY_KEEP_CONNECTIONS_OPEN,exports);
     SetConstant("TRANSPORT_TLS_ONLY_KEEP_CONNECTIONS_OPEN",GETDNS_TRANSPORT_TLS_ONLY_KEEP_CONNECTIONS_OPEN,exports);
     SetConstant("TRANSPORT_TLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN",GETDNS_TRANSPORT_TLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN,exports);
+    SetConstant("CONTEXT_CODE_NAMESPACES",GETDNS_CONTEXT_CODE_NAMESPACES,exports);
+    SetConstant("CONTEXT_CODE_RESOLUTION_TYPE",GETDNS_CONTEXT_CODE_RESOLUTION_TYPE,exports);
+    SetConstant("CONTEXT_CODE_FOLLOW_REDIRECTS",GETDNS_CONTEXT_CODE_FOLLOW_REDIRECTS,exports);
+    SetConstant("CONTEXT_CODE_UPSTREAM_RECURSIVE_SERVERS",GETDNS_CONTEXT_CODE_UPSTREAM_RECURSIVE_SERVERS,exports);
+    SetConstant("CONTEXT_CODE_DNS_ROOT_SERVERS",GETDNS_CONTEXT_CODE_DNS_ROOT_SERVERS,exports);
+    SetConstant("CONTEXT_CODE_DNS_TRANSPORT",GETDNS_CONTEXT_CODE_DNS_TRANSPORT,exports);
+    SetConstant("CONTEXT_CODE_LIMIT_OUTSTANDING_QUERIES",GETDNS_CONTEXT_CODE_LIMIT_OUTSTANDING_QUERIES,exports);
+    SetConstant("CONTEXT_CODE_APPEND_NAME",GETDNS_CONTEXT_CODE_APPEND_NAME,exports);
+    SetConstant("CONTEXT_CODE_SUFFIX",GETDNS_CONTEXT_CODE_SUFFIX,exports);
+    SetConstant("CONTEXT_CODE_DNSSEC_TRUST_ANCHORS",GETDNS_CONTEXT_CODE_DNSSEC_TRUST_ANCHORS,exports);
+    SetConstant("CONTEXT_CODE_EDNS_MAXIMUM_UDP_PAYLOAD_SIZE",GETDNS_CONTEXT_CODE_EDNS_MAXIMUM_UDP_PAYLOAD_SIZE,exports);
+    SetConstant("CONTEXT_CODE_EDNS_EXTENDED_RCODE",GETDNS_CONTEXT_CODE_EDNS_EXTENDED_RCODE,exports);
+    SetConstant("CONTEXT_CODE_EDNS_VERSION",GETDNS_CONTEXT_CODE_EDNS_VERSION,exports);
+    SetConstant("CONTEXT_CODE_EDNS_DO_BIT",GETDNS_CONTEXT_CODE_EDNS_DO_BIT,exports);
+    SetConstant("CONTEXT_CODE_DNSSEC_ALLOWED_SKEW",GETDNS_CONTEXT_CODE_DNSSEC_ALLOWED_SKEW,exports);
+    SetConstant("CONTEXT_CODE_MEMORY_FUNCTIONS",GETDNS_CONTEXT_CODE_MEMORY_FUNCTIONS,exports);
+    SetConstant("CONTEXT_CODE_TIMEOUT",GETDNS_CONTEXT_CODE_TIMEOUT,exports);
+    SetConstant("CONTEXT_CODE_IDLE_TIMEOUT",GETDNS_CONTEXT_CODE_IDLE_TIMEOUT,exports);
     SetConstant("CONTEXT_CODE_TLS_AUTHENTICATION",GETDNS_CONTEXT_CODE_TLS_AUTHENTICATION,exports);
+    SetConstant("CONTEXT_CODE_EDNS_CLIENT_SUBNET_PRIVATE",GETDNS_CONTEXT_CODE_EDNS_CLIENT_SUBNET_PRIVATE,exports);
+    SetConstant("CONTEXT_CODE_TLS_QUERY_PADDING_BLOCKSIZE",GETDNS_CONTEXT_CODE_TLS_QUERY_PADDING_BLOCKSIZE,exports);
+    SetConstant("CONTEXT_CODE_PUBKEY_PINSET",GETDNS_CONTEXT_CODE_PUBKEY_PINSET,exports);
     SetConstant("TRANSPORT_UDP",GETDNS_TRANSPORT_UDP,exports);
     SetConstant("TRANSPORT_TCP",GETDNS_TRANSPORT_TCP,exports);
     SetConstant("TRANSPORT_TLS",GETDNS_TRANSPORT_TLS,exports);
     SetConstant("AUTHENTICATION_NONE",GETDNS_AUTHENTICATION_NONE,exports);
     SetConstant("AUTHENTICATION_HOSTNAME",GETDNS_AUTHENTICATION_HOSTNAME,exports);
+    SetConstant("AUTHENTICATION_REQUIRED",GETDNS_AUTHENTICATION_REQUIRED,exports);
     SetConstant("APPEND_NAME_ALWAYS",GETDNS_APPEND_NAME_ALWAYS,exports);
     SetConstant("APPEND_NAME_ONLY_TO_SINGLE_LABEL_AFTER_FAILURE",GETDNS_APPEND_NAME_ONLY_TO_SINGLE_LABEL_AFTER_FAILURE,exports);
     SetConstant("APPEND_NAME_ONLY_TO_MULTIPLE_LABEL_NAME_AFTER_FAILURE",GETDNS_APPEND_NAME_ONLY_TO_MULTIPLE_LABEL_NAME_AFTER_FAILURE,exports);
@@ -211,4 +236,5 @@ void GNConstants::Init(Local<Object> target) {
     SetConstant("RCODE_BADNAME",GETDNS_RCODE_BADNAME,exports);
     SetConstant("RCODE_BADALG",GETDNS_RCODE_BADALG,exports);
     SetConstant("RCODE_BADTRUNC",GETDNS_RCODE_BADTRUNC,exports);
+    SetConstant("RCODE_COOKIE",GETDNS_RCODE_COOKIE,exports);
 }