diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 29a33f4..015c38a 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -8211,44 +8211,67 @@
 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
 
 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
-int mbedtls_ssl_parse_servername_ext( mbedtls_ssl_context *ssl,
-                                             const unsigned char *buf,
-                                             const unsigned char *end )
+/*
+ * mbedtls_ssl_parse_server_name_ext
+ *
+ * Structure of server_name extension:
+ *
+ *  enum {
+ *        host_name(0), (255)
+ *     } NameType;
+ *  opaque HostName<1..2^16-1>;
+ *
+ *  struct {
+ *          NameType name_type;
+ *          select (name_type) {
+ *             case host_name: HostName;
+ *           } name;
+ *     } ServerName;
+ *  struct {
+ *          ServerName server_name_list<1..2^16-1>
+ *     } ServerNameList;
+ */
+int mbedtls_ssl_parse_server_name_ext( mbedtls_ssl_context *ssl,
+                                       const unsigned char *buf,
+                                       const unsigned char *end )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     const unsigned char *p = buf;
-    size_t servername_list_size, hostname_len;
-    const unsigned char *servername_end;
+    size_t server_name_list_len, hostname_len;
+    const unsigned char *server_name_list_end;
 
     if( ssl->conf->p_sni == NULL )
     {
-        MBEDTLS_SSL_DEBUG_MSG( 3, ( "No SNI callback configured. Skip SNI parsing." ) );
+        MBEDTLS_SSL_DEBUG_MSG(
+                3, ( "No SNI callback configured. Skip SNI parsing." ) );
         return( 0 );
     }
 
     MBEDTLS_SSL_DEBUG_MSG( 3, ( "Parse ServerName extension" ) );
 
     MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
-    servername_list_size = MBEDTLS_GET_UINT16_BE( p, 0 );
+    server_name_list_len = MBEDTLS_GET_UINT16_BE( p, 0 );
     p += 2;
 
-    MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, servername_list_size );
-    servername_end = p + servername_list_size;
-    while ( p < servername_end )
+    MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, server_name_list_len );
+    server_name_list_end = p + server_name_list_len;
+    while ( p < server_name_list_end )
     {
-        MBEDTLS_SSL_CHK_BUF_READ_PTR( p, servername_end, 3 );
+        MBEDTLS_SSL_CHK_BUF_READ_PTR( p, server_name_list_end, 3 );
         hostname_len = MBEDTLS_GET_UINT16_BE( p, 1 );
-        MBEDTLS_SSL_CHK_BUF_READ_PTR( p, servername_end, hostname_len + 3 );
+        MBEDTLS_SSL_CHK_BUF_READ_PTR( p, server_name_list_end,
+                                      hostname_len + 3 );
 
         if( p[0] == MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME )
         {
             ret = ssl->conf->f_sni( ssl->conf->p_sni,
-                                   ssl, p + 3, hostname_len );
+                                    ssl, p + 3, hostname_len );
             if( ret != 0 )
             {
                 MBEDTLS_SSL_DEBUG_RET( 1, "sni_wrapper", ret );
-                mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-                                               MBEDTLS_SSL_ALERT_MSG_UNRECOGNIZED_NAME );
+                mbedtls_ssl_send_alert_message(
+                        ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+                        MBEDTLS_SSL_ALERT_MSG_UNRECOGNIZED_NAME );
                 return( MBEDTLS_ERR_SSL_UNRECOGNIZED_NAME );
             }
             return( 0 );