Add CHANGES for [GL #2846]

This commit slightly extends the 'masterformat' system test to include
several use cases for the 'masterfile-format auto' feature.

CHANGES

@@ -1,3 +1,9 @@
+5703.	[func]		Implement a 'masterfile-format auto' feature which
+			automatically recognizes the existing master file's
+			format or uses the default format for the particular
+			zone type when there is no existing master file.
+			[GL #2846]
+
 5702.	[bug]		Improve compatibility with DNS-over-HTTPS clients by
 			allowing HTTP/2 request headers in any order. [GL #2875]
 

bin/check/named-checkconf.c

@@ -437,6 +437,18 @@ configure_zone(const char *vclass, const char *view, const cfg_obj_t *zconfig,
 			masterformat = dns_masterformat_raw;
 		} else if (strcasecmp(masterformatstr, "map") == 0) {
 			masterformat = dns_masterformat_map;
+		} else if (strcasecmp(masterformatstr, "auto") == 0) {
+			result = dns_master_masterformat_autodetect(
+				zfile, &masterformat);
+			if (result != ISC_R_SUCCESS &&
+			    result != ISC_R_FILENOTFOUND) {
+				fprintf(stderr,
+					"%s/%s/%s: 'masterfile-format auto': "
+					"%s\n",
+					view, zname, zclass,
+					dns_result_totext(result));
+				return (result);
+			}
 		} else {
 			INSIST(0);
 			ISC_UNREACHABLE();

bin/named/named.conf.rst

@@ -301,7 +301,7 @@ OPTIONS
   	lmdb-mapsize sizeval;
   	lock-file ( quoted_string | none );
   	managed-keys-directory quoted_string;
-  	masterfile-format ( map | raw | text );
+  	masterfile-format ( map | raw | text | auto );
   	masterfile-style ( full | relative );
   	match-mapped-addresses boolean;
   	max-cache-size ( default | unlimited | sizeval | percentage );
@@ -708,7 +708,7 @@ VIEW
   	    ) integer integer
   	    integer
   	    quoted_string; ... };, deprecated
-  	masterfile-format ( map | raw | text );
+  	masterfile-format ( map | raw | text | auto );
   	masterfile-style ( full | relative );
   	match-clients { address_match_element; ... };
   	match-destinations { address_match_element; ... };
@@ -927,7 +927,7 @@ VIEW
   		ixfr-from-differences boolean;
   		journal quoted_string;
   		key-directory quoted_string;
-  		masterfile-format ( map | raw | text );
+  		masterfile-format ( map | raw | text | auto );
   		masterfile-style ( full | relative );
   		masters [ port integer ] [ dscp integer ] { (
   		    remote-servers | ipv4_address [ port integer ] |
@@ -1044,7 +1044,7 @@ ZONE
   	ixfr-from-differences boolean;
   	journal quoted_string;
   	key-directory quoted_string;
-  	masterfile-format ( map | raw | text );
+  	masterfile-format ( map | raw | text | auto );
   	masterfile-style ( full | relative );
   	masters [ port integer ] [ dscp integer ] { ( remote-servers
   	    | ipv4_address [ port integer ] | ipv6_address [ port

bin/named/zoneconf.c

@@ -1053,6 +1053,19 @@ named_zone_configure(const cfg_obj_t *config, const cfg_obj_t *vconfig,
 			masterformat = dns_masterformat_raw;
 		} else if (strcasecmp(masterformatstr, "map") == 0) {
 			masterformat = dns_masterformat_map;
+		} else if (strcasecmp(masterformatstr, "auto") == 0) {
+			result = dns_master_masterformat_autodetect(
+				filename, &masterformat);
+			if (result != ISC_R_SUCCESS &&
+			    result != ISC_R_FILENOTFOUND) {
+				isc_log_write(
+					named_g_lctx, NAMED_LOGCATEGORY_GENERAL,
+					NAMED_LOGMODULE_SERVER, ISC_LOG_ERROR,
+					"zone '%s': "
+					"'masterfile-format auto': %s\n",
+					zname, dns_result_totext(result));
+				return (ISC_R_FAILURE);
+			}
 		} else {
 			INSIST(0);
 			ISC_UNREACHABLE();
@@ -1068,7 +1081,9 @@ named_zone_configure(const cfg_obj_t *config, const cfg_obj_t *vconfig,
 			cfg_obj_log(obj, named_g_lctx, ISC_LOG_ERROR,
 				    "zone '%s': 'masterfile-style' "
 				    "can only be used with "
-				    "'masterfile-format text'",
+				    "'masterfile-format text' or "
+				    "'masterfile-format auto' with an "
+				    "auto-detected format of 'text'",
 				    zname);
 			return (ISC_R_FAILURE);
 		}
@@ -1089,7 +1104,9 @@ named_zone_configure(const cfg_obj_t *config, const cfg_obj_t *vconfig,
 		isc_log_write(named_g_lctx, NAMED_LOGCATEGORY_GENERAL,
 			      NAMED_LOGMODULE_SERVER, ISC_LOG_ERROR,
 			      "zone '%s': 'max-zone-ttl' is not compatible "
-			      "with 'masterfile-format map'",
+			      "with 'masterfile-format map' or "
+			      "'masterfile-format auto' with an "
+			      "auto-detected format of 'map'",
 			      zname);
 		return (ISC_R_FAILURE);
 	} else if (result == ISC_R_SUCCESS) {

bin/tests/system/masterformat/clean.sh

@@ -23,6 +23,7 @@ rm -f ./*/named.run
 rm -f ./ns2/example.db
 rm -f ./ns2/transfer.db.*
 rm -f ./ns2/formerly-text.db
+rm -f ./ns2/formerly-text-presently-auto-text.db
 rm -f ./ns2/db-*
 rm -f ./ns2/large.bk
 rm -f ./ns3/example.db.map ./ns3/dynamic.db.map

bin/tests/system/masterformat/ns1/named.conf.in

@@ -67,6 +67,17 @@ zone "transfer4" {
 	allow-transfer { any; };
 };
 
+zone "transfer5" {
+	type primary;
+	file "example.db";
+	allow-transfer { any; };
+};
+
+zone "transfer6" {
+	type primary;
+	file "example.db";
+	allow-transfer { any; };
+};
 
 zone "large" {
 	type primary;

bin/tests/system/masterformat/ns2/formerly-text-presently-auto-text.db.in

@@ -0,0 +1,46 @@
+; Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+;
+; This Source Code Form is subject to the terms of the Mozilla Public
+; License, v. 2.0. If a copy of the MPL was not distributed with this
+; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+;
+; See the COPYRIGHT file distributed with this work for additional
+; information regarding copyright ownership.
+
+$ORIGIN .
+$TTL 86400	; 1 day
+transfer5		IN SOA	ns.transfer5. hostmaster.transfer5. (
+				1          ; serial
+				3600       ; refresh (1 hour)
+				1800       ; retry (30 minutes)
+				1814400    ; expire (3 weeks)
+				3          ; minimum (3 seconds)
+				)
+			NS	ns.transfer5.
+$ORIGIN transfer5.
+a			A	10.53.0.1
+			A	10.53.0.2
+aaaa			AAAA	2001:db8::53
+cname			CNAME	cname-target
+dname			DNAME	dname-target
+$TTL 300	; 5 minutes
+dnskey			DNSKEY	256 3 13 (
+				TEcpWeW1mJp+OujqyInMbjGRODJIYen/4kMR
+				wO6zW3RzrvmNIMgFag6G uXofiSwJ6YDeQ0O
+				3uhPJsJ7ivpbh+w==
+				)
+ds			DS	30795 1 1 (
+				310D27F4D82C1FC2400704EA9939FE6E1CEAA3B9 )
+$TTL 86400	; 1 day
+mx			MX	10 mail
+ns			A	10.53.0.1
+$TTL 600	; 10 minutes
+nsec			NSEC	nsecnext.transfer5. NS DS RRSIG NSEC
+$TTL 300	; 5 minutes
+rrsig			RRSIG	SOA 1 0 300 (
+				20050714214747 20050614214747 30795 .
+				yi/RRPAQmn6rnjDQaCqVValBa+ICF00ZldKfZSDaoew5
+				mMUh83DlrrPPNeAxrzMSNzDGlJ6PfdyIFgzPn/CvthF4
+				kjBUAiJTp4r2zhlaUJQ+QFo+drYXYgVJo6aA36fj )
+$TTL 86400	; 1 day
+txt			TXT	"this is text"

bin/tests/system/masterformat/ns2/formerly-text.db.in

@@ -9,15 +9,15 @@
 
 $ORIGIN .
 $TTL 86400	; 1 day
-transfer3		IN SOA	ns.transfer3. hostmaster.transfer3. (
+transfer4		IN SOA	ns.transfer4. hostmaster.transfer4. (
 				1          ; serial
 				3600       ; refresh (1 hour)
 				1800       ; retry (30 minutes)
 				1814400    ; expire (3 weeks)
 				3          ; minimum (3 seconds)
 				)
-			NS	ns.transfer3.
-$ORIGIN transfer3.
+			NS	ns.transfer4.
+$ORIGIN transfer4.
 a			A	10.53.0.1
 			A	10.53.0.2
 aaaa			AAAA	2001:db8::53
@@ -35,7 +35,7 @@ $TTL 86400	; 1 day
 mx			MX	10 mail
 ns			A	10.53.0.1
 $TTL 600	; 10 minutes
-nsec			NSEC	nsecnext.transfer3. NS DS RRSIG NSEC
+nsec			NSEC	nsecnext.transfer4. NS DS RRSIG NSEC
 $TTL 300	; 5 minutes
 rrsig			RRSIG	SOA 1 0 300 (
 				20050714214747 20050614214747 30795 .

bin/tests/system/masterformat/ns2/named.conf.in

@@ -35,17 +35,31 @@ zone "transfer1" {
 zone "transfer2" {
 	type secondary;
 	primaries { 10.53.0.1; };
-	masterfile-format text;
-	file "transfer.db.txt";
+	masterfile-format auto;
+	file "transfer.db.auto.raw";
 };
 
 zone "transfer3" {
 	type secondary;
 	primaries { 10.53.0.1; };
-	file "formerly-text.db";
+	masterfile-format text;
+	file "transfer.db.txt";
 };
 
 zone "transfer4" {
+	type secondary;
+	primaries { 10.53.0.1; };
+	file "formerly-text.db";
+};
+
+zone "transfer5" {
+	type secondary;
+	primaries { 10.53.0.1; };
+	masterfile-format auto;
+	file "formerly-text-presently-auto-text.db";
+};
+
+zone "transfer6" {
 	type secondary;
 	primaries { 10.53.0.1; };
 	masterfile-format text;

bin/tests/system/masterformat/ns3/named.conf.in

@@ -31,7 +31,7 @@ controls {
 
 zone "example" {
 	type primary;
-	masterfile-format map;
+	masterfile-format auto;
 	file "example.db.map";
 };
 

bin/tests/system/masterformat/setup.sh

@@ -20,6 +20,7 @@ copy_setports ns3/named.conf.in ns3/named.conf
 
 cp ns1/example.db ns2/
 cp ns2/formerly-text.db.in ns2/formerly-text.db
+cp ns2/formerly-text-presently-auto-text.db.in ns2/formerly-text-presently-auto-text.db
 cp ns1/large.db.in ns1/large.db
 awk 'END {
 	 for (i = 0; i < 512; i++ ) { print "a TXT", i; }

bin/tests/system/masterformat/tests.sh

@@ -144,7 +144,7 @@ status=$((status+ret))
 echo_i "waiting for transfers to complete"
 for i in 0 1 2 3 4 5 6 7 8 9
 do
-	test -f ns2/transfer.db.raw -a -f ns2/transfer.db.txt && break
+	test -f ns2/transfer.db.raw -a -f ns2/transfer.db.auto.raw -a -f ns2/transfer.db.txt && break
 	sleep 1
 done
 
@@ -155,6 +155,13 @@ n=$((n+1))
 [ $ret -eq 0 ] || echo_i "failed"
 status=$((status+ret))
 
+echo_i "checking that secondary was saved in raw format when configured as auto ($n)"
+ret=0
+israw ns2/transfer.db.raw || ret=1
+n=$((n+1))
+[ $ret -eq 0 ] || echo_i "failed"
+status=$((status+ret))
+
 echo_i "checking that secondary was saved in text format when configured ($n)"
 ret=0
 israw ns2/transfer.db.txt && ret=1
@@ -183,6 +190,20 @@ n=$((n+1))
 [ $ret -eq 0 ] || echo_i "failed"
 status=$((status+ret))
 
+echo_i "checking that secondary formerly in text format is now in text format too, using auto ($n)"
+for i in 0 1 2 3 4 5 6 7 8 9
+do
+    ret=0
+    test -f ns2/formerly-text-presently-auto-text.db > /dev/null 2>&1 || ret=1
+    israw ns2/formerly-text-presently-auto-text.db > /dev/null 2>&1 && ret=1
+    ismap ns2/formerly-text-presently-auto-text.db > /dev/null 2>&1 && ret=1
+    [ $ret -eq 0 ] && break
+    sleep 1
+done
+n=$((n+1))
+[ $ret -eq 0 ] || echo_i "failed"
+status=$((status+ret))
+
 echo_i "checking that large rdatasets loaded ($n)"
 for i in 0 1 2 3 4 5 6 7 8 9
 do

doc/arm/reference.rst

@@ -3582,10 +3582,17 @@ Tuning
    ``masterfile-format`` statement within the ``zone`` or ``view`` block
    in the configuration file.
 
+   When set to ``auto``, BIND 9 will try to automatically detect the used
+   format, based on the existing file on the disk. When the file does not
+   exist ``auto`` will be equal to the default value of ``text``, except
+   for secondary and mirror zones in which case ``auto`` will be equal to
+   the default value of ``raw``.
+
 ``masterfile-style``
    This specifies the formatting of zone files during dump, when the
-   ``masterfile-format`` is ``text``. This option is ignored with any
-   other ``masterfile-format``.
+   ``masterfile-format`` is ``text`` or when ``masterfile-format`` is
+   ``auto`` with an auto-detected value of ``text``. This option is ignored
+   with any other ``masterfile-format``.
 
    When set to ``relative``, records are printed in a multi-line format,
    with owner names expressed relative to a shared origin. When set to
@@ -5125,9 +5132,10 @@ The following options can be specified in a ``dnssec-policy`` statement:
   ``max-zone-ttl``
     Like the ``max-zone-ttl`` zone option, this specifies the maximum
     permissible TTL value, in seconds, for the zone.  When loading a
-    zone file using a ``masterfile-format`` of ``text`` or ``raw``, any
-    record encountered with a TTL higher than ``max-zone-ttl`` is capped
-    at the maximum permissible TTL value.
+    zone file using a ``masterfile-format`` of ``text`` or ``raw``, or
+    using ``masterfile-format`` of ``auto`` with auto-detected values of
+    either ``text`` or ``raw``, any record encountered with a TTL higher
+    than ``max-zone-ttl`` is capped at the maximum permissible TTL value.
 
     This is needed in DNSSEC-maintained zones because when rolling to a
     new DNSKEY, the old key needs to remain available until RRSIG

doc/man/named.conf.5in

@@ -368,7 +368,7 @@ options {
       lmdb\-mapsize sizeval;
       lock\-file ( quoted_string | none );
       managed\-keys\-directory quoted_string;
-      masterfile\-format ( map | raw | text );
+      masterfile\-format ( map | raw | text | auto );
       masterfile\-style ( full | relative );
       match\-mapped\-addresses boolean;
       max\-cache\-size ( default | unlimited | sizeval | percentage );
@@ -811,7 +811,7 @@ view string [ class ] {
           ) integer integer
           integer
           quoted_string; ... };, deprecated
-      masterfile\-format ( map | raw | text );
+      masterfile\-format ( map | raw | text | auto );
       masterfile\-style ( full | relative );
       match\-clients { address_match_element; ... };
       match\-destinations { address_match_element; ... };
@@ -1030,7 +1030,7 @@ view string [ class ] {
               ixfr\-from\-differences boolean;
               journal quoted_string;
               key\-directory quoted_string;
-              masterfile\-format ( map | raw | text );
+              masterfile\-format ( map | raw | text | auto );
               masterfile\-style ( full | relative );
               masters [ port integer ] [ dscp integer ] { (
                   remote\-servers | ipv4_address [ port integer ] |
@@ -1151,7 +1151,7 @@ zone string [ class ] {
       ixfr\-from\-differences boolean;
       journal quoted_string;
       key\-directory quoted_string;
-      masterfile\-format ( map | raw | text );
+      masterfile\-format ( map | raw | text | auto );
       masterfile\-style ( full | relative );
       masters [ port integer ] [ dscp integer ] { ( remote\-servers
           | ipv4_address [ port integer ] | ipv6_address [ port

doc/misc/master.zoneopt

@@ -33,7 +33,7 @@ zone <string> [ <class> ] {
 	ixfr-from-differences <boolean>;
 	journal <quoted_string>;
 	key-directory <quoted_string>;
-	masterfile-format ( map | raw | text );
+	masterfile-format ( map | raw | text | auto );
 	masterfile-style ( full | relative );
 	max-ixfr-ratio ( unlimited | <percentage> );
 	max-journal-size ( default | unlimited | <sizeval> );

doc/misc/master.zoneopt.rst

@@ -35,7 +35,7 @@
   	ixfr-from-differences <boolean>;
   	journal <quoted_string>;
   	key-directory <quoted_string>;
-  	masterfile-format ( map | raw | text );
+  	masterfile-format ( map | raw | text | auto );
   	masterfile-style ( full | relative );
   	max-ixfr-ratio ( unlimited | <percentage> );
   	max-journal-size ( default | unlimited | <sizeval> );

doc/misc/mirror.zoneopt

@@ -13,7 +13,7 @@ zone <string> [ <class> ] {
 	file <quoted_string>;
 	ixfr-from-differences <boolean>;
 	journal <quoted_string>;
-	masterfile-format ( map | raw | text );
+	masterfile-format ( map | raw | text | auto );
 	masterfile-style ( full | relative );
 	masters [ port <integer> ] [ dscp <integer> ] { ( <remote-servers> | <ipv4_address> [ port <integer> ] | <ipv6_address> [ port <integer> ] ) [ key <string> ] [ tls <string> ]; ... };
 	max-ixfr-ratio ( unlimited | <percentage> );

doc/misc/mirror.zoneopt.rst

@@ -15,7 +15,7 @@
   	file <quoted_string>;
   	ixfr-from-differences <boolean>;
   	journal <quoted_string>;
-  	masterfile-format ( map | raw | text );
+  	masterfile-format ( map | raw | text | auto );
   	masterfile-style ( full | relative );
   	masters [ port <integer> ] [ dscp <integer> ] { ( <remote-servers> | <ipv4_address> [ port <integer> ] | <ipv6_address> [ port <integer> ] ) [ key <string> ] [ tls <string> ]; ... };
   	max-ixfr-ratio ( unlimited | <percentage> );

doc/misc/named.conf.rst

@@ -289,7 +289,7 @@ OPTIONS
   	lmdb-mapsize sizeval;
   	lock-file ( quoted_string | none );
   	managed-keys-directory quoted_string;
-  	masterfile-format ( map | raw | text );
+  	masterfile-format ( map | raw | text | auto );
   	masterfile-style ( full | relative );
   	match-mapped-addresses boolean;
   	max-cache-size ( default | unlimited | sizeval | percentage );
@@ -644,7 +644,7 @@ VIEW
   	    ) integer integer
   	    integer
   	    quoted_string; ... };, deprecated
-  	masterfile-format ( map | raw | text );
+  	masterfile-format ( map | raw | text | auto );
   	masterfile-style ( full | relative );
   	match-clients { address_match_element; ... };
   	match-destinations { address_match_element; ... };
@@ -856,7 +856,7 @@ VIEW
   		ixfr-from-differences boolean;
   		journal quoted_string;
   		key-directory quoted_string;
-  		masterfile-format ( map | raw | text );
+  		masterfile-format ( map | raw | text | auto );
   		masterfile-style ( full | relative );
   		masters [ port integer ] [ dscp integer ] { ( masters
   		    | ipv4_address [ port integer ] | ipv6_address [
@@ -959,7 +959,7 @@ ZONE
   	ixfr-from-differences boolean;
   	journal quoted_string;
   	key-directory quoted_string;
-  	masterfile-format ( map | raw | text );
+  	masterfile-format ( map | raw | text | auto );
   	masterfile-style ( full | relative );
   	masters [ port integer ] [ dscp integer ] { ( masters |
   	    ipv4_address [ port integer ] | ipv6_address [ port

doc/misc/options

@@ -225,7 +225,7 @@ options {
         lmdb-mapsize <sizeval>;
         lock-file ( <quoted_string> | none );
         managed-keys-directory <quoted_string>;
-        masterfile-format ( map | raw | text );
+        masterfile-format ( map | raw | text | auto );
         masterfile-style ( full | relative );
         match-mapped-addresses <boolean>;
         max-cache-size ( default | unlimited | <sizeval> | <percentage> );
@@ -587,7 +587,7 @@ view <string> [ <class> ] {
             ) <integer> <integer>
             <integer>
             <quoted_string>; ... }; // may occur multiple times, deprecated
-        masterfile-format ( map | raw | text );
+        masterfile-format ( map | raw | text | auto );
         masterfile-style ( full | relative );
         match-clients { <address_match_element>; ... };
         match-destinations { <address_match_element>; ... };
@@ -808,7 +808,7 @@ view <string> [ <class> ] {
                 ixfr-from-differences <boolean>;
                 journal <quoted_string>;
                 key-directory <quoted_string>;
-                masterfile-format ( map | raw | text );
+                masterfile-format ( map | raw | text | auto );
                 masterfile-style ( full | relative );
                 masters [ port <integer> ] [ dscp <integer> ] { (
                     <remote-servers> | <ipv4_address> [ port <integer> ] |
@@ -921,7 +921,7 @@ zone <string> [ <class> ] {
         ixfr-from-differences <boolean>;
         journal <quoted_string>;
         key-directory <quoted_string>;
-        masterfile-format ( map | raw | text );
+        masterfile-format ( map | raw | text | auto );
         masterfile-style ( full | relative );
         masters [ port <integer> ] [ dscp <integer> ] { ( <remote-servers>
             | <ipv4_address> [ port <integer> ] | <ipv6_address> [ port

doc/misc/options.active

@@ -224,7 +224,7 @@ options {
         lmdb-mapsize <sizeval>;
         lock-file ( <quoted_string> | none );
         managed-keys-directory <quoted_string>;
-        masterfile-format ( map | raw | text );
+        masterfile-format ( map | raw | text | auto );
         masterfile-style ( full | relative );
         match-mapped-addresses <boolean>;
         max-cache-size ( default | unlimited | <sizeval> | <percentage> );
@@ -584,7 +584,7 @@ view <string> [ <class> ] {
             ) <integer> <integer>
             <integer>
             <quoted_string>; ... }; // may occur multiple times, deprecated
-        masterfile-format ( map | raw | text );
+        masterfile-format ( map | raw | text | auto );
         masterfile-style ( full | relative );
         match-clients { <address_match_element>; ... };
         match-destinations { <address_match_element>; ... };
@@ -803,7 +803,7 @@ view <string> [ <class> ] {
                 ixfr-from-differences <boolean>;
                 journal <quoted_string>;
                 key-directory <quoted_string>;
-                masterfile-format ( map | raw | text );
+                masterfile-format ( map | raw | text | auto );
                 masterfile-style ( full | relative );
                 masters [ port <integer> ] [ dscp <integer> ] { (
                     <remote-servers> | <ipv4_address> [ port <integer> ] |
@@ -915,7 +915,7 @@ zone <string> [ <class> ] {
         ixfr-from-differences <boolean>;
         journal <quoted_string>;
         key-directory <quoted_string>;
-        masterfile-format ( map | raw | text );
+        masterfile-format ( map | raw | text | auto );
         masterfile-style ( full | relative );
         masters [ port <integer> ] [ dscp <integer> ] { ( <remote-servers>
             | <ipv4_address> [ port <integer> ] | <ipv6_address> [ port

doc/misc/options.grammar.rst

@@ -144,7 +144,7 @@
   	lmdb-mapsize <sizeval>;
   	lock-file ( <quoted_string> | none );
   	managed-keys-directory <quoted_string>;
-  	masterfile-format ( map | raw | text );
+  	masterfile-format ( map | raw | text | auto );
   	masterfile-style ( full | relative );
   	match-mapped-addresses <boolean>;
   	max-cache-size ( default | unlimited | <sizeval> | <percentage> );

doc/misc/redirect.zoneopt

@@ -4,7 +4,7 @@ zone <string> [ <class> ] {
 	allow-query-on { <address_match_element>; ... };
 	dlz <string>;
 	file <quoted_string>;
-	masterfile-format ( map | raw | text );
+	masterfile-format ( map | raw | text | auto );
 	masterfile-style ( full | relative );
 	masters [ port <integer> ] [ dscp <integer> ] { ( <remote-servers> | <ipv4_address> [ port <integer> ] | <ipv6_address> [ port <integer> ] ) [ key <string> ] [ tls <string> ]; ... };
 	max-records <integer>;

doc/misc/redirect.zoneopt.rst

@@ -6,7 +6,7 @@
   	allow-query-on { <address_match_element>; ... };
   	dlz <string>;
   	file <quoted_string>;
-  	masterfile-format ( map | raw | text );
+  	masterfile-format ( map | raw | text | auto );
   	masterfile-style ( full | relative );
   	masters [ port <integer> ] [ dscp <integer> ] { ( <remote-servers> | <ipv4_address> [ port <integer> ] | <ipv6_address> [ port <integer> ] ) [ key <string> ] [ tls <string> ]; ... };
   	max-records <integer>;

doc/misc/slave.zoneopt

@@ -25,7 +25,7 @@ zone <string> [ <class> ] {
 	ixfr-from-differences <boolean>;
 	journal <quoted_string>;
 	key-directory <quoted_string>;
-	masterfile-format ( map | raw | text );
+	masterfile-format ( map | raw | text | auto );
 	masterfile-style ( full | relative );
 	masters [ port <integer> ] [ dscp <integer> ] { ( <remote-servers> | <ipv4_address> [ port <integer> ] | <ipv6_address> [ port <integer> ] ) [ key <string> ] [ tls <string> ]; ... };
 	max-ixfr-ratio ( unlimited | <percentage> );

doc/misc/slave.zoneopt.rst

@@ -27,7 +27,7 @@
   	ixfr-from-differences <boolean>;
   	journal <quoted_string>;
   	key-directory <quoted_string>;
-  	masterfile-format ( map | raw | text );
+  	masterfile-format ( map | raw | text | auto );
   	masterfile-style ( full | relative );
   	masters [ port <integer> ] [ dscp <integer> ] { ( <remote-servers> | <ipv4_address> [ port <integer> ] | <ipv6_address> [ port <integer> ] ) [ key <string> ] [ tls <string> ]; ... };
   	max-ixfr-ratio ( unlimited | <percentage> );

doc/misc/stub.zoneopt

@@ -9,7 +9,7 @@ zone <string> [ <class> ] {
 	file <quoted_string>;
 	forward ( first | only );
 	forwarders [ port <integer> ] [ dscp <integer> ] { ( <ipv4_address> | <ipv6_address> ) [ port <integer> ] [ dscp <integer> ]; ... };
-	masterfile-format ( map | raw | text );
+	masterfile-format ( map | raw | text | auto );
 	masterfile-style ( full | relative );
 	masters [ port <integer> ] [ dscp <integer> ] { ( <remote-servers> | <ipv4_address> [ port <integer> ] | <ipv6_address> [ port <integer> ] ) [ key <string> ] [ tls <string> ]; ... };
 	max-records <integer>;

doc/misc/stub.zoneopt.rst

@@ -11,7 +11,7 @@
   	file <quoted_string>;
   	forward ( first | only );
   	forwarders [ port <integer> ] [ dscp <integer> ] { ( <ipv4_address> | <ipv6_address> ) [ port <integer> ] [ dscp <integer> ]; ... };
-  	masterfile-format ( map | raw | text );
+  	masterfile-format ( map | raw | text | auto );
   	masterfile-style ( full | relative );
   	masters [ port <integer> ] [ dscp <integer> ] { ( <remote-servers> | <ipv4_address> [ port <integer> ] | <ipv6_address> [ port <integer> ] ) [ key <string> ] [ tls <string> ]; ... };
   	max-records <integer>;

lib/bind9/check.c

@@ -3350,6 +3350,13 @@ check_zoneconf(const cfg_obj_t *zconfig, const cfg_obj_t *voptions,
 			masterformat = dns_masterformat_raw;
 		} else if (strcasecmp(masterformatstr, "map") == 0) {
 			masterformat = dns_masterformat_map;
+		} else if (strcasecmp(masterformatstr, "auto") == 0) {
+			if (ztype == CFG_ZONE_SLAVE || ztype == CFG_ZONE_MIRROR)
+			{
+				masterformat = dns_masterformat_raw;
+			} else {
+				masterformat = dns_masterformat_text;
+			}
 		} else {
 			INSIST(0);
 			ISC_UNREACHABLE();

lib/dns/include/dns/master.h

@@ -257,6 +257,34 @@ dns_master_initrawheader(dns_masterrawheader_t *header);
  * Initializes the header for a raw master file, setting all
  * values to zero.
  */
+
+isc_result_t
+dns_master_masterformat_autodetect(const char *	       master_file,
+				   dns_masterformat_t *result_masterformat);
+/*%<
+ * Autodetects the master file's format.
+ *
+ * There are no heuristics, it is expected that the given master file is in one
+ * of the supported formats - "text", "raw", or "map".
+ *
+ * The "raw" and "map" type master files have a specific header, which will
+ * be recognized by this function. If neither of those formats are detected,
+ * the functions will assume that the given master file is in "text" format.
+ *
+ * Requires:
+ *\li	'master_file' points to a valid string.
+ *\li	'result_masterformat != NULL'.
+ *
+ * Ensures:
+ *\li	'*result_masterformat' is not altered when the return value is not
+ *		ISC_R_SUCCESS.
+ *
+ * Returns:
+ *\li	ISC_R_SUCCESS upon successfully detection.
+ *\li	ISC_R_FILENOTFOUND when the master_file was not found.
+ *\li	Any isc_stdio_read() error code.
+ *\li	Any isc_stdio_close() error code.
+ */
 ISC_LANG_ENDDECLS
 
 #endif /* DNS_MASTER_H */

lib/dns/master.c

@@ -16,6 +16,7 @@
 
 #include <isc/atomic.h>
 #include <isc/event.h>
+#include <isc/file.h>
 #include <isc/lex.h>
 #include <isc/magic.h>
 #include <isc/mem.h>
@@ -3226,3 +3227,56 @@ void
 dns_master_initrawheader(dns_masterrawheader_t *header) {
 	memset(header, 0, sizeof(dns_masterrawheader_t));
 }
+
+isc_result_t
+dns_master_masterformat_autodetect(const char *master_file,
+				   dns_masterformat_t *result_masterformat) {
+	FILE *f;
+	dns_masterrawheader_t header;
+	unsigned char data[sizeof header.format + sizeof header.version];
+	isc_buffer_t target;
+	isc_result_t result;
+
+	if (!isc_file_exists(master_file)) {
+		return (ISC_R_FILENOTFOUND);
+	}
+
+	result = isc_stdio_open(master_file, "rb", &f);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	dns_master_initrawheader(&header);
+
+	isc_buffer_init(&target, data, sizeof data);
+
+	result = isc_stdio_read(data, sizeof data, 1, f, NULL);
+	if (result != ISC_R_SUCCESS) {
+		/*
+		 * We can't report multiple errors so ignore
+		 * the result of isc_stdio_close().
+		 */
+		(void)isc_stdio_close(f);
+		return (result);
+	}
+
+	result = isc_stdio_close(f);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	isc_buffer_add(&target, (unsigned int)sizeof data);
+	header.format = isc_buffer_getuint32(&target);
+	header.version = isc_buffer_getuint32(&target);
+
+	if (((dns_masterformat_t)header.format == dns_masterformat_raw ||
+	     (dns_masterformat_t)header.format == dns_masterformat_map) &&
+	    header.version <= (uint32_t)DNS_RAWFORMAT_VERSION)
+	{
+		*result_masterformat = (dns_masterformat_t)header.format;
+	} else {
+		*result_masterformat = dns_masterformat_text;
+	}
+
+	return (ISC_R_SUCCESS);
+}

lib/isccfg/namedconf.c

@@ -1410,7 +1410,8 @@ static cfg_type_t cfg_type_mustbesecure = {
 	cfg_doc_tuple,	&cfg_rep_tuple,	 mustbesecure_fields
 };
 
-static const char *masterformat_enums[] = { "map", "raw", "text", NULL };
+static const char *masterformat_enums[] = { "map", "raw", "text", "auto",
+					    NULL };
 static cfg_type_t cfg_type_masterformat = {
 	"masterformat", cfg_parse_enum,	 cfg_print_ustring,
 	cfg_doc_enum,	&cfg_rep_string, &masterformat_enums