Export built-in default configuration for named binary

It might be useful to display built-in configuration with all its
values. It should make it easier to test what default values has changed
in a new release.

Related: #1326

CHANGES

@@ -1,3 +1,6 @@
+5880.	[func]		Add new named command-line option -C to print built-in
+			defaults. [GL #1326]
+
 5879.	[contrib]	dlz: Add FALLTHROUGH and UNREACHABLE macros. [GL #3306]
 
 5878.	[func]		Check the algorithm name or OID embedded at the start

bin/named/config.c

@@ -334,6 +334,11 @@ named_config_parsedefaults(cfg_parser_t *parser, cfg_obj_t **conf) {
 				 CFG_PCTX_NODEPRECATED, conf));
 }
 
+const char *
+named_config_getdefault() {
+	return (defaultconf);
+}
+
 isc_result_t
 named_config_get(cfg_obj_t const *const *maps, const char *name,
 		 const cfg_obj_t **obj) {

bin/named/include/named/config.h

@@ -27,6 +27,9 @@
 isc_result_t
 named_config_parsedefaults(cfg_parser_t *parser, cfg_obj_t **conf);
 
+const char *
+named_config_getdefault(void);
+
 isc_result_t
 named_config_get(cfg_obj_t const *const *maps, const char *name,
 		 const cfg_obj_t **obj);

bin/named/include/named/main.h

@@ -24,7 +24,7 @@
 /*
  * Commandline arguments for named;
  */
-#define NAMED_MAIN_ARGS "46A:c:d:D:E:fFgL:M:m:n:N:p:sS:t:T:U:u:vVx:X:"
+#define NAMED_MAIN_ARGS "46A:c:Cd:D:E:fFgL:M:m:n:N:p:sS:t:T:U:u:vVx:X:"
 
 noreturn void
 named_main_earlyfatal(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);

bin/named/main.c

@@ -316,7 +316,7 @@ usage(void) {
 			"             [-X lockfile] [-m "
 			"{usage|trace|record|size|mctx}]\n"
 			"             [-M fill|nofill]\n"
-			"usage: named [-v|-V]\n");
+			"usage: named [-v|-V|-C]\n");
 }
 
 static void
@@ -778,6 +778,11 @@ parse_command_line(int argc, char *argv[]) {
 			named_g_conffile = isc_commandline_argument;
 			named_g_conffileset = true;
 			break;
+		case 'C':
+			printf("# Built-in default values. "
+			       "This is NOT the run-time configuration!\n");
+			printf("%s", named_config_getdefault());
+			exit(0);
 		case 'd':
 			named_g_debuglevel = parse_int(isc_commandline_argument,
 						       "debug "

bin/named/named.rst

@@ -21,7 +21,7 @@ named - Internet domain name server
 Synopsis
 ~~~~~~~~
 
-:program:`named` [ [**-4**] | [**-6**] ] [**-c** config-file] [**-d** debug-level] [**-D** string] [**-E** engine-name] [**-f**] [**-g**] [**-L** logfile] [**-M** option] [**-m** flag] [**-n** #cpus] [**-p** port] [**-s**] [**-t** directory] [**-U** #listeners] [**-u** user] [**-v**] [**-V**] [**-X** lock-file]
+:program:`named` [ [**-4**] | [**-6**] ] [**-c** config-file] [**-C**] [**-d** debug-level] [**-D** string] [**-E** engine-name] [**-f**] [**-g**] [**-L** logfile] [**-M** option] [**-m** flag] [**-n** #cpus] [**-p** port] [**-s**] [**-t** directory] [**-U** #listeners] [**-u** user] [**-v**] [**-V**] [**-X** lock-file]
 
 Description
 ~~~~~~~~~~~
@@ -55,6 +55,14 @@ Options
    due to to a possible ``directory`` option in the configuration file,
    ``config-file`` should be an absolute pathname.
 
+.. option:: -C
+
+   This option prints out the default built-in configuration and exits.
+
+   NOTE: This is for debugging purposes only and is not an
+   accurate representation of the actual configuration used by :iscman:`named`
+   at runtime.
+
 .. option:: -d debug-level
 
    This option sets the daemon's debug level to ``debug-level``. Debugging traces from

doc/man/named.8in

@@ -32,7 +32,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 named \- Internet domain name server
 .SH SYNOPSIS
 .sp
-\fBnamed\fP [ [\fB\-4\fP] | [\fB\-6\fP] ] [\fB\-c\fP config\-file] [\fB\-d\fP debug\-level] [\fB\-D\fP string] [\fB\-E\fP engine\-name] [\fB\-f\fP] [\fB\-g\fP] [\fB\-L\fP logfile] [\fB\-M\fP option] [\fB\-m\fP flag] [\fB\-n\fP #cpus] [\fB\-p\fP port] [\fB\-s\fP] [\fB\-t\fP directory] [\fB\-U\fP #listeners] [\fB\-u\fP user] [\fB\-v\fP] [\fB\-V\fP] [\fB\-X\fP lock\-file]
+\fBnamed\fP [ [\fB\-4\fP] | [\fB\-6\fP] ] [\fB\-c\fP config\-file] [\fB\-C\fP] [\fB\-d\fP debug\-level] [\fB\-D\fP string] [\fB\-E\fP engine\-name] [\fB\-f\fP] [\fB\-g\fP] [\fB\-L\fP logfile] [\fB\-M\fP option] [\fB\-m\fP flag] [\fB\-n\fP #cpus] [\fB\-p\fP port] [\fB\-s\fP] [\fB\-t\fP directory] [\fB\-U\fP #listeners] [\fB\-u\fP user] [\fB\-v\fP] [\fB\-V\fP] [\fB\-X\fP lock\-file]
 .SH DESCRIPTION
 .sp
 \fBnamed\fP is a Domain Name System (DNS) server, part of the BIND 9
@@ -66,6 +66,15 @@ due to to a possible \fBdirectory\fP option in the configuration file,
 .UNINDENT
 .INDENT 0.0
 .TP
+.B \-C
+This option prints out the default built\-in configuration and exits.
+.sp
+NOTE: This is for debugging purposes only and is not an
+accurate representation of the actual configuration used by \fI\%named\fP
+at runtime.
+.UNINDENT
+.INDENT 0.0
+.TP
 .B \-d debug\-level
 This option sets the daemon\(aqs debug level to \fBdebug\-level\fP\&. Debugging traces from
 \fBnamed\fP become more verbose as the debug level increases.