server identification: add hostname into configuration

refs #2463

Change-Id: I1d923b8c985a861d3bbf8afea4c522a5bba48fea

samples/knot.full.conf

@@ -20,6 +20,9 @@ system {
   # Version of the server (see RFC 4892). Not used yet.
   version "1.2";
 
+  # Host name of the server (see RFC 4892). Not used yet.
+  hostname "myserver0";
+
   # Server identifier
   # Use string format "text"
   # Or hexstring 0x01ab00

src/knot/conf/cf-lex.l

@@ -74,6 +74,7 @@ BLANK [ \t\n]
 [\!\$\%\^\&\*\(\)\/\+\-\@\{\}\;\,] { return yytext[0]; }
 system          { lval.t = yytext; return SYSTEM; }
 identity        { lval.t = yytext; return IDENTITY; }
+hostname        { lval.t = yytext; return HOSTNAME; }
 version         { lval.t = yytext; return SVERSION; }
 nsid            { lval.t = yytext; return NSID; }
 storage         { lval.t = yytext; return STORAGE; }

src/knot/conf/cf-parse.y

@@ -384,7 +384,7 @@ static int conf_mask(void* scanner, int nval, int prefixlen) {
 %token <tok> SIZE
 %token <tok> BOOL
 
-%token <tok> SYSTEM IDENTITY SVERSION NSID STORAGE KEY KEYS
+%token <tok> SYSTEM IDENTITY HOSTNAME SVERSION NSID STORAGE KEY KEYS
 %token <tok> TSIG_ALGO_NAME
 %token <tok> WORKERS
 %token <tok> USER
@@ -509,6 +509,7 @@ system:
    SYSTEM '{'
  | system SVERSION TEXT ';' { new_config->version = $3.t; }
  | system IDENTITY TEXT ';' { new_config->identity = $3.t; }
+ | system HOSTNAME TEXT ';' { new_config->hostname = $3.t; }
  | system NSID HEXSTR ';' { new_config->nsid = $3.t; new_config->nsid_len = $3.l; }
  | system NSID TEXT ';' { new_config->nsid = $3.t; new_config->nsid_len = strlen(new_config->nsid); }
  | system STORAGE TEXT ';' { new_config->storage = $3.t; }

src/knot/conf/conf.c

@@ -669,6 +669,10 @@ void conf_truncate(conf_t *conf, int unload_hooks)
 		free(conf->identity);
 		conf->identity = 0;
 	}
+	if (conf->hostname) {
+		free(conf->hostname);
+		conf->hostname = 0;
+	}
 	if (conf->version) {
 		free(conf->version);
 		conf->version = 0;

src/knot/conf/conf.h

@@ -191,6 +191,7 @@ typedef struct conf_t {
 	 */
 	char *filename; /*!< Name of the config file. */
 	char *identity; /*!< Identity to return on CH TXT id.server. */
+	char *hostname; /*!< Host name to return on CH TXT hostname.{bind,server} */
 	char *version;  /*!< Version for CH TXT version.{bind|server} */
 	char *storage;  /*!< Persistent storage path for databases and such. */
 	char *pidfile;  /*!< PID file path. */