From: Aram Sargsyan <aram@isc.org>
Date: Mon, 10 Feb 2025 13:11:18 +0000 (+0000)
Subject: Use named Service Parameter Keys (SvcParamKeys) by default
X-Git-Tag: ondrej/lock-free-qpzone-reads-v1~58^2~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c6e369547860a1dd8e4fd1af53bab182270aa90a;p=thirdparty%2Fbind9.git

Use named Service Parameter Keys (SvcParamKeys) by default

When converting SVCB records to text representation use named
SvcParamKeys values unless backward-compatible mode is activated,
in which case the values which were not defined initially in
RFC9460 and were added later (see [1]) are converted to opaque
"keyN" syntax, like, for example, "key7" instead of "dohpath".

[1] https://www.iana.org/assignments/dns-svcb/dns-svcb.xhtml

Co-authored-by: sdomi <ja@sdomi.pl>
---

diff --git a/lib/dns/include/dns/rdata.h b/lib/dns/include/dns/rdata.h
index 2123bbc927a..ac255b2028b 100644
--- a/lib/dns/include/dns/rdata.h
+++ b/lib/dns/include/dns/rdata.h
@@ -173,6 +173,9 @@ struct dns_rdata {
 /*% Print AAAA record fully expanded */
 #define DNS_STYLEFLAG_EXPANDAAAA 0x00000020ULL
 
+/*% Print non-initial Service Parameter Keys in backward-compatible format */
+#define DNS_STYLEFLAG_SVCPARAMKEYCOMPAT 0x00000040ULL
+
 #define DNS_RDATA_DOWNCASE	 DNS_NAME_DOWNCASE
 #define DNS_RDATA_CHECKNAMES	 DNS_NAME_CHECKNAMES
 #define DNS_RDATA_CHECKNAMESFAIL DNS_NAME_CHECKNAMESFAIL
diff --git a/lib/dns/rdata/in_1/svcb_64.c b/lib/dns/rdata/in_1/svcb_64.c
index 8764617688f..b5c431c70bc 100644
--- a/lib/dns/rdata/in_1/svcb_64.c
+++ b/lib/dns/rdata/in_1/svcb_64.c
@@ -377,12 +377,12 @@ svc_fromtext(isc_textregion_t *region, isc_buffer_t *target) {
 
 static const char *
 svcparamkey(unsigned short value, enum encoding *encoding, char *buf,
-	    size_t len) {
+	    size_t len, bool compat) {
 	size_t i;
 	int n;
 
 	for (i = 0; i < ARRAY_SIZE(sbpr); i++) {
-		if (sbpr[i].value == value && sbpr[i].initial) {
+		if (sbpr[i].value == value && (sbpr[i].initial || !compat)) {
 			*encoding = sbpr[i].encoding;
 			return sbpr[i].name;
 		}
@@ -639,6 +639,7 @@ generic_totext_in_svcb(ARGS_TOTEXT) {
 	char buf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 	unsigned short num;
 	int n;
+	bool compat = (tctx->flags & DNS_STYLEFLAG_SVCPARAMKEYCOMPAT) != 0;
 
 	REQUIRE(rdata->length != 0);
 
@@ -674,8 +675,9 @@ generic_totext_in_svcb(ARGS_TOTEXT) {
 		INSIST(region.length >= 2);
 		num = uint16_fromregion(&region);
 		isc_region_consume(&region, 2);
-		RETERR(str_totext(svcparamkey(num, &encoding, buf, sizeof(buf)),
-				  target));
+		RETERR(str_totext(
+			svcparamkey(num, &encoding, buf, sizeof(buf), compat),
+			target));
 
 		INSIST(region.length >= 2);
 		num = uint16_fromregion(&region);
@@ -747,7 +749,8 @@ generic_totext_in_svcb(ARGS_TOTEXT) {
 				num = uint16_fromregion(&r);
 				isc_region_consume(&r, 2);
 				RETERR(str_totext(svcparamkey(num, &encoding,
-							      buf, sizeof(buf)),
+							      buf, sizeof(buf),
+							      compat),
 						  target));
 				if (r.length != 0) {
 					RETERR(str_totext(",", target));