Merge pull request #28 from ArvidNorr/tcp_nodelay

Support for TCP keepalive and TCP no_delay added

common/os_calls.c

@@ -325,9 +325,11 @@ g_getchar(void)
 }
 
 /*****************************************************************************/
+/*Returns 0 on success*/
 int APP_CC
 g_tcp_set_no_delay(int sck)
 {
+  int ret = 1 ; /*error*/    
 #if defined(_WIN32)
   int option_value;
   int option_len;
@@ -345,11 +347,55 @@ g_tcp_set_no_delay(int sck)
     {
       option_value = 1;
       option_len = sizeof(option_value);
-      setsockopt(sck, IPPROTO_TCP, TCP_NODELAY, (char*)&option_value,
-                 option_len);
+      if(setsockopt(sck, IPPROTO_TCP, TCP_NODELAY, (char*)&option_value,
+                 option_len)==0)
+      {
+	  ret = 0 ; /* success */
       }
     }
-  return 0;
+  }
+  else
+  {   
+    g_writeln("Error getting tcp_nodelay");  
+  }
+  return ret;
+}
+
+/*****************************************************************************/
+/*Returns 0 on success*/
+int APP_CC
+g_tcp_set_keepalive(int sck)
+{
+  int ret = 1 ; /*error*/    
+#if defined(_WIN32)
+  int option_value;
+  int option_len;
+#else
+  int option_value;
+  unsigned int option_len;
+#endif
+
+  option_len = sizeof(option_value);
+  /* SOL_TCP IPPROTO_TCP */
+  if (getsockopt(sck, SOL_SOCKET, SO_KEEPALIVE, (char*)&option_value,
+                 &option_len) == 0)
+  {
+    if (option_value == 0)
+    {
+      option_value = 1;
+      option_len = sizeof(option_value);
+      if(setsockopt(sck, SOL_SOCKET, SO_KEEPALIVE, (char*)&option_value,
+                 option_len)==0)
+      {
+	  ret = 0 ; /* success */
+      }
+    }
+  }
+  else
+  {   
+    g_writeln("Error getting tcp_keepalive");  
+  }
+  return ret;
 }
 
 /*****************************************************************************/

common/os_calls.h

@@ -64,6 +64,8 @@ g_getchar(void);
 int APP_CC
 g_tcp_set_no_delay(int sck);
 int APP_CC
+g_tcp_set_keepalive(int sck);
+int APP_CC
 g_tcp_socket(void);
 int APP_CC
 g_tcp_local_socket(void);

xrdp/xrdp.ini

@@ -7,6 +7,12 @@ crypt_level=low
 channel_code=1
 max_bpp=24
 fork=yes
+# regulate if the listening socket use socket option tcp_nodelay
+# no buffering will be performed in the TCP stack
+tcp_nodelay=yes
+# regulate if the listening socket use socket option keepalive
+# if the network connection disappear without close messages the connection will be closed
+tcp_keepalive=yes
 #black=000000
 #grey=d6d3ce
 #dark_grey=808080

xrdp/xrdp_listen.c

@@ -134,6 +134,7 @@ xrdp_process_run(void* in_val)
 static int
 xrdp_listen_get_port_address(char* port, int port_bytes,
                              char* address, int address_bytes,
+                             int *tcp_nodelay, int *tcp_keepalive,
                              struct xrdp_startup_params* startup_param)
 {
   int fd;
@@ -151,6 +152,8 @@ xrdp_listen_get_port_address(char* port, int port_bytes,
   /* see if port or address is in xrdp.ini file */
   g_snprintf(cfg_file, 255, "%s/xrdp.ini", XRDP_CFG_PATH);
   fd = g_file_open(cfg_file);
+  *tcp_nodelay = 0 ;
+  *tcp_keepalive = 0 ;
   if (fd > 0)
   {
     names = list_create();
@@ -189,6 +192,28 @@ xrdp_listen_get_port_address(char* port, int port_bytes,
               startup_param->fork = 1;
             }
           }
+          if (g_strcasecmp(val, "tcp_nodelay") == 0)
+          {
+            val = (char*)list_get_item(values, index);
+            if ((g_strcasecmp(val, "yes") == 0) ||
+                (g_strcasecmp(val, "on") == 0) ||
+                (g_strcasecmp(val, "true") == 0) ||
+                (g_atoi(val) != 0))
+            {
+              *tcp_nodelay = 1 ;
+            }
+          }
+          if (g_strcasecmp(val, "tcp_keepalive") == 0)
+          {
+            val = (char*)list_get_item(values, index);
+            if ((g_strcasecmp(val, "yes") == 0) ||
+                (g_strcasecmp(val, "on") == 0) ||
+                (g_strcasecmp(val, "true") == 0) ||
+                (g_atoi(val) != 0))
+            {
+              *tcp_keepalive = 1 ;
+            }
+          }
         }
       }
     }
@@ -283,19 +308,37 @@ xrdp_listen_main_loop(struct xrdp_listen* self)
   tbus term_obj;
   tbus sync_obj;
   tbus done_obj;
+  int tcp_nodelay;
+  int tcp_keepalive;
 
   self->status = 1;
   if (xrdp_listen_get_port_address(port, sizeof(port),
                                    address, sizeof(address),
+                                   &tcp_nodelay, &tcp_keepalive,
                                    self->startup_params) != 0)
   {
     g_writeln("xrdp_listen_main_loop: xrdp_listen_get_port failed");
     self->status = -1;
     return 1;
   }
+  /*Create socket*/
   error = trans_listen_address(self->listen_trans, port, address);
   if (error == 0)
   {
+    if(tcp_nodelay)
+    {
+      if(g_tcp_set_no_delay(self->listen_trans->sck))
+      {
+        g_writeln("Error setting tcp_nodelay");
+      }
+    }
+    if(tcp_keepalive)
+    {
+      if(g_tcp_set_keepalive(self->listen_trans->sck))
+      {
+        g_writeln("Error setting tcp_keepalive");
+      }
+    }
     self->listen_trans->trans_conn_in = xrdp_listen_conn_in;
     self->listen_trans->callback_data = self;
     term_obj = g_get_term_event(); /*Global termination event */