treewide: remove branches supporting old knot

Our Makefile required >= 2.6.4 for some time already.
It's pretty straightforward, except for zonefile.lua.in -> zonefile.lua

.gitignore

@@ -50,7 +50,6 @@ _obj
 /daemon/kresd
 /daemon/lua/*.inc
 /daemon/lua/trust_anchors.lua
-/daemon/lua/zonefile.lua
 /tests/test_array
 /tests/test_lru
 /tests/test_map

daemon/daemon.mk

@@ -63,17 +63,11 @@ ifneq ($(SED),)
 	$(INSTALL) -m 0644 doc/kresd.8 $(DESTDIR)$(MANDIR)/man8/
 endif
 daemon-clean: kresd-clean
-	@$(RM) daemon/lua/*.inc daemon/lua/trust_anchors.lua \
-		daemon/lua/zonefile.lua
+	@$(RM) daemon/lua/*.inc daemon/lua/trust_anchors.lua
 
 daemon/lua/trust_anchors.lua: daemon/lua/trust_anchors.lua.in
 	@$(call quiet,SED,$<) -e "s|@ETCDIR@|$(ETCDIR)|g;s|@KEYFILE_DEFAULT@|$(KEYFILE_DEFAULT)|g" $< > $@
 
-LIBZSCANNER_COMMENTS := \
-	$(shell pkg-config libzscanner --atleast-version=2.4.2 && echo true || echo false)
-daemon/lua/zonefile.lua: daemon/lua/zonefile.lua.in
-	@$(call quiet,SED,$<) -e "s|@LIBZSCANNER_COMMENTS@|$(LIBZSCANNER_COMMENTS)|g" $< > $@
-
 daemon/lua/kres-gen.lua: | $(libkres)
 	@echo "WARNING: regenerating $@"
 	@# the sed saves some space(s)

daemon/lua/zonefile.lua.in → daemon/lua/zonefile.lua

@@ -169,7 +169,6 @@ ffi.metatype( zs_scanner_t, {
 			return ffi.string(libzscanner.zs_strerror(zs.error.code))
 		end,
 		current_comment = function(zs)
-			if not @LIBZSCANNER_COMMENTS@ then return nil end -- support in libzscanner
 			if zs.buffer_length > 0 then
 				return ffi.string(zs.buffer, zs.buffer_length - 1)
 			else

lib/defines.h

@@ -72,7 +72,6 @@ static inline int KR_COLD kr_error(int x) {
 #define KR_DNS_TLS_PORT 853
 #define KR_EDNS_VERSION 0
 #define KR_EDNS_PAYLOAD 4096 /* Default UDP payload (max unfragmented UDP is 1452B) */
-#define KR_DEFAULT_TLS_PADDING 468 /* Default EDNS(0) Padding is 468 */
 #define KR_CACHE_DEFAULT_TTL_MIN (5) /* avoid bursts of queries */
 #define KR_CACHE_DEFAULT_TTL_MAX (6 * 24 * 3600) /* 6 days, like the root NS TTL */
 

lib/dnssec.c

@@ -257,41 +257,6 @@ static int kr_rrset_validate_with_key(kr_rrset_validation_ctx_t *vctx,
 	return vctx->result;
 }
 
-/* Fallbacks: implemented in newer libdnssec.
- * Note: changing some from true to false is NOT enough to fully remove the support. */
-#if KNOT_VERSION_HEX < ((2 << 16) | (6 << 8) | 0)
-	static bool dnssec_algorithm_key_support(dnssec_key_algorithm_t algo)
-	{
-		switch (algo) {
-		case DNSSEC_KEY_ALGORITHM_DSA_SHA1:
-		case DNSSEC_KEY_ALGORITHM_DSA_SHA1_NSEC3:
-		case DNSSEC_KEY_ALGORITHM_RSA_SHA1:
-		case DNSSEC_KEY_ALGORITHM_RSA_SHA1_NSEC3:
-		case DNSSEC_KEY_ALGORITHM_RSA_SHA256:
-		case DNSSEC_KEY_ALGORITHM_RSA_SHA512:
-		case DNSSEC_KEY_ALGORITHM_ECDSA_P256_SHA256:
-		case DNSSEC_KEY_ALGORITHM_ECDSA_P384_SHA384:
-			return true;
-		//case DNSSEC_KEY_ALGORITHM_ED25519:
-		//case DNSSEC_KEY_ALGORITHM_ED448:
-		default:
-			return false;
-		}
-	}
-
-	static bool dnssec_algorithm_digest_support(dnssec_key_digest_t algo)
-	{
-		switch (algo) {
-		case DNSSEC_KEY_DIGEST_SHA1:
-		case DNSSEC_KEY_DIGEST_SHA256:
-		case DNSSEC_KEY_DIGEST_SHA384:
-			return true;
-		default:
-			return false;
-		};
-	}
-#endif
-
 static bool kr_ds_algo_support(const knot_rrset_t *ta)
 {
 	for (uint16_t i = 0; i < ta->rrs.rr_count; ++i) {

lib/resolve.c

@@ -536,12 +536,7 @@ static int answer_padding(struct kr_request *request)
 	int32_t pad_bytes = -1;
 
 	if (padding == -1) { /* use the default padding policy from libknot */
-#if KNOT_VERSION_HEX < ((2 << 16) | (4 << 8) | 3)
-		/* no knot_edns_default_padding_size available in libknot */
-		padding = KR_DEFAULT_TLS_PADDING;
-#else
 		pad_bytes =  knot_edns_default_padding_size(answer, opt_rr);
-#endif
 	}
 	if (padding >= 2) {
 		int32_t max_pad_bytes = knot_edns_get_payload(opt_rr) - (answer->size + knot_rrset_size(opt_rr));

modules/cookies/cookiemonster.c

@@ -258,11 +258,7 @@ int check_response(kr_layer_t *ctx, knot_pkt_t *pkt)
 		return KR_STATE_FAIL;
 	}
 
-#if KNOT_VERSION_HEX >= ((2 << 16) | (4 << 8)) // just renamed function since 2.4.0
 	uint16_t rcode = knot_pkt_ext_rcode(pkt);
-#else
-	uint16_t rcode = knot_pkt_get_ext_rcode(pkt);
-#endif
 	if (rcode == KNOT_RCODE_BADCOOKIE) {
 		struct kr_query *next = NULL;
 		if (!(qry->flags.BADCOOKIE_AGAIN)) {