Declare the keep-response-order obsolete

The keep-response-order option has been introduced when TCP pipelining
has been introduced to BIND 9 as a failsafe for possibly non-compliant
clients.

Declare the keep-response-order obsolete as all DNS clients should
either support out-of-order processing or don't send more DNS queries
until the DNS response for the previous one has been received.

bin/named/config.c

@@ -68,7 +68,6 @@ options {\n\
 			    "\
 	heartbeat-interval 60;\n\
 	interface-interval 60;\n\
-#	keep-response-order {none;};\n\
 	listen-on {any;};\n\
 	listen-on-v6 {any;};\n\
 #	lock-file \"" NAMED_LOCALSTATEDIR "/run/named/named.lock\";\n\

bin/named/named.conf.rst

@@ -301,7 +301,6 @@ OPTIONS
   	ipv4only-server string;
   	ixfr-from-differences ( primary | master | secondary | slave |
   	    boolean );
-  	keep-response-order { address_match_element; ... };
   	key-directory quoted_string;
   	lame-ttl duration;
   	listen-on [ port integer ] [ dscp

bin/tests/system/pipelined/ns4/named.conf.in

@@ -20,7 +20,6 @@ options {
 	pid-file "named.pid";
 	listen-on { 10.53.0.4; };
 	listen-on-v6 { none; };
-	keep-response-order { 10.53.0.7/32; };
 	recursion yes;
 	dnssec-validation yes;
 	notify yes;

doc/arm/reference.rst

@@ -153,8 +153,8 @@ and a negated match denies access. If there is no match, access is
 denied. The clauses ``allow-notify``, ``allow-recursion``,
 ``allow-recursion-on``, ``allow-query``, ``allow-query-on``,
 ``allow-query-cache``, ``allow-query-cache-on``, ``allow-transfer``,
-``allow-update``, ``allow-update-forwarding``, ``blackhole``, and
+``allow-update``, ``allow-update-forwarding``, and ``blackhole``
-``keep-response-order`` all use address match lists. Similarly, the
+all use address match lists. Similarly, the
 ``listen-on`` option causes the server to refuse queries on any of
 the machine's addresses which do not match the list.
 
@@ -2463,12 +2463,6 @@ for details on how to specify IP address lists.
    from or use to resolve a query. Queries from these addresses are not
    responded to. The default is ``none``.
 
-``keep-response-order``
-   This specifies a list of addresses to which the server sends responses
-   to TCP queries, in the same order in which they were received. This
-   disables the processing of TCP queries in parallel. The default is
-   ``none``.
-
 ``no-case-compress``
    This specifies a list of addresses which require responses to use
    case-insensitive compression. This ACL can be used when ``named``

doc/man/named.conf.5in

@@ -357,7 +357,6 @@ options {
       ipv4only\-server string;
       ixfr\-from\-differences ( primary | master | secondary | slave |
           boolean );
-      keep\-response\-order { address_match_element; ... };
       key\-directory quoted_string;
       lame\-ttl duration;
       listen\-on [ port integer ] [ dscp

doc/misc/options

@@ -214,7 +214,7 @@ options {
         ipv4only-server <string>;
         ixfr-from-differences ( primary | master | secondary | slave |
             <boolean> );
-        keep-response-order { <address_match_element>; ... };
+        keep-response-order { <address_match_element>; ... }; // obsolete
         key-directory <quoted_string>;
         lame-ttl <duration>;
         listen-on [ port <integer> ] [ dscp

doc/misc/options.active

@@ -213,7 +213,6 @@ options {
         ipv4only-server <string>;
         ixfr-from-differences ( primary | master | secondary | slave |
             <boolean> );
-        keep-response-order { <address_match_element>; ... };
         key-directory <quoted_string>;
         lame-ttl <duration>;
         listen-on [ port <integer> ] [ dscp

doc/misc/options.grammar.rst

@@ -144,7 +144,6 @@
   	ipv4only-server <string>;
   	ixfr-from-differences ( primary | master | secondary | slave |
   	    <boolean> );
-  	keep-response-order { <address_match_element>; ... };
   	key-directory <quoted_string>;
   	lame-ttl <duration>;
   	listen-on [ port <integer> ] [ dscp

lib/isccfg/namedconf.c

@@ -1274,7 +1274,8 @@ static cfg_clausedef_t options_clauses[] = {
 	{ "host-statistics-max", NULL, CFG_CLAUSEFLAG_ANCIENT },
 	{ "hostname", &cfg_type_qstringornone, 0 },
 	{ "interface-interval", &cfg_type_duration, 0 },
-	{ "keep-response-order", &cfg_type_bracketed_aml, 0 },
+	{ "keep-response-order", &cfg_type_bracketed_aml,
+	  CFG_CLAUSEFLAG_OBSOLETE },
 	{ "listen-on", &cfg_type_listenon, CFG_CLAUSEFLAG_MULTI },
 	{ "listen-on-v6", &cfg_type_listenon, CFG_CLAUSEFLAG_MULTI },
 	{ "lock-file", &cfg_type_qstringornone, 0 },