[settings] Add fetch_ipv4_array_setting()

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/core/settings.c

  *
  * @v settings		Settings block, or NULL to search all blocks
  * @v setting		Setting to fetch
- * @v inp		IPv4 address to fill in
+ * @v inp		IPv4 addresses to fill in
+ * @v count		Maximum number of IPv4 addresses
  * @ret len		Length of setting, or negative error
  */
-int fetch_ipv4_setting ( struct settings *settings, struct setting *setting,
-			 struct in_addr *inp ) {
+int fetch_ipv4_array_setting ( struct settings *settings,
+			       struct setting *setting,
+			       struct in_addr *inp, unsigned int count ) {
 	int len;
 
-	len = fetch_setting ( settings, setting, inp, sizeof ( *inp ) );
+	len = fetch_setting ( settings, setting, inp,
+			      ( sizeof ( *inp ) * count ) );
 	if ( len < 0 )
 		return len;
-	if ( len < ( int ) sizeof ( *inp ) )
+	if ( ( len % sizeof ( *inp ) ) != 0 )
 		return -ERANGE;
 	return len;
 }
 
+/**
+ * Fetch value of IPv4 address setting
+ *
+ * @v settings		Settings block, or NULL to search all blocks
+ * @v setting		Setting to fetch
+ * @v inp		IPv4 address to fill in
+ * @ret len		Length of setting, or negative error
+ */
+int fetch_ipv4_setting ( struct settings *settings, struct setting *setting,
+			 struct in_addr *inp ) {
+	return fetch_ipv4_array_setting ( settings, setting, inp, 1 );
+}
+
 /**
  * Fetch value of signed integer setting
  *

src/include/ipxe/settings.h

 extern int fetch_string_setting_copy ( struct settings *settings,
 				       struct setting *setting,
 				       char **data );
+extern int fetch_ipv4_array_setting ( struct settings *settings,
+				      struct setting *setting,
+				      struct in_addr *inp,
+				      unsigned int count );
 extern int fetch_ipv4_setting ( struct settings *settings,
 				struct setting *setting, struct in_addr *inp );
 extern int fetch_int_setting ( struct settings *settings,