diff --git a/drivers/can/can.c b/drivers/can/can.c
index d387a37bff..e1499291f4 100644
--- a/drivers/can/can.c
+++ b/drivers/can/can.c
@@ -967,9 +967,11 @@ static inline ssize_t can_rtrread(FAR struct file *filep,
 
 static int can_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
 {
-  FAR struct inode     *inode = filep->f_inode;
-  FAR struct can_dev_s *dev   = inode->i_private;
-  int                   ret   = OK;
+  FAR struct inode        *inode  = filep->f_inode;
+  FAR struct can_dev_s    *dev    = inode->i_private;
+  FAR struct can_reader_s *reader = filep->f_priv;
+
+  int                     ret     = OK;
 
   caninfo("cmd: %d arg: %ld\n", cmd, arg);
 
@@ -985,8 +987,71 @@ static int can_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
        */
 
       case CANIOC_RTR:
-        ret = can_rtrread(filep,
-                          (FAR struct canioc_rtr_s *)((uintptr_t)arg));
+        {
+          ret = can_rtrread(filep,
+                            (FAR struct canioc_rtr_s *)((uintptr_t)arg));
+        }
+        break;
+
+      /* CANIOC_IFLUSH: Flush data received but not read. No argument.      */
+
+      case CANIOC_IFLUSH:
+        {
+          reader->fifo.rx_head = 0;
+          reader->fifo.rx_tail = 0;
+
+          /* invoke lower half ioctl */
+
+          ret = dev_ioctl(dev, cmd, arg);
+        }
+        break;
+
+      /* CANIOC_OFLUSH: Flush data written but not transmitted. No argument */
+
+      case CANIOC_OFLUSH:
+        {
+          dev->cd_xmit.tx_head  = 0;
+          dev->cd_xmit.tx_queue = 0;
+          dev->cd_xmit.tx_tail  = 0;
+
+          /* invoke lower half ioctl */
+
+          ret = dev_ioctl(dev, cmd, arg);
+        }
+        break;
+
+      /* CANIOC_IOFLUSH: Flush data received but not read and data written
+       *                 but not yet transmitted
+       */
+
+      case CANIOC_IOFLUSH:
+        {
+          dev->cd_xmit.tx_head  = 0;
+          dev->cd_xmit.tx_queue = 0;
+          dev->cd_xmit.tx_tail  = 0;
+          reader->fifo.rx_head = 0;
+          reader->fifo.rx_tail = 0;
+
+          /* invoke lower half ioctl */
+
+          ret = dev_ioctl(dev, cmd, arg);
+        }
+        break;
+
+      /* FIONWRITE: Return the number of CAN messages in the send queue     */
+
+      case FIONWRITE:
+        {
+          *(uint8_t *)arg = dev->cd_xmit.tx_tail;
+        }
+        break;
+
+      /* FIONREAD: Return the number of CAN messages in the receive FIFO    */
+
+      case FIONREAD:
+        {
+          *(uint8_t *)arg = reader->fifo.rx_tail;
+        }
         break;
 
       /* Not a "built-in" ioctl command.. perhaps it is unique to this
@@ -994,7 +1059,9 @@ static int can_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
        */
 
       default:
-        ret = dev_ioctl(dev, cmd, arg);
+        {
+          ret = dev_ioctl(dev, cmd, arg);
+        }
         break;
     }
 
diff --git a/include/nuttx/can/can.h b/include/nuttx/can/can.h
index c26bd11ed8..d26c503e46 100644
--- a/include/nuttx/can/can.h
+++ b/include/nuttx/can/can.h
@@ -221,6 +221,31 @@
  *                   is returned with the errno variable set to indicate the
  *                   nature of the error.
  *   Dependencies:   None
+ *
+ * CANIOC_IFLUSH
+ *   Description:    Flush data received but not read
+ *   Argument:       None
+ *   Returned Value: Zero (OK) is returned on success.  Otherwise -1 (ERROR)
+ *                   is returned with the errno variable set to indicate the
+ *                   nature of the error.
+ *   Dependencies:   None
+ *
+ * CANIOC_OFLUSH
+ *   Description:    Flush data written but not transmitted
+ *   Argument:       None
+ *   Returned Value: Zero (OK) is returned on success.  Otherwise -1 (ERROR)
+ *                   is returned with the errno variable set to indicate the
+ *                   nature of the error.
+ *   Dependencies:   None
+ *
+ * CANIOC_IOFLUSH
+ *   Description:    Flush data received but not read and data written but
+ *                   not transmitted
+ *   Argument:       None
+ *   Returned Value: Zero (OK) is returned on success.  Otherwise -1 (ERROR)
+ *                   is returned with the errno variable set to indicate the
+ *                   nature of the error.
+ *   Dependencies:   None
  */
 
 #define CANIOC_RTR                _CANIOC(1)
@@ -235,9 +260,12 @@
 #define CANIOC_BUSOFF_RECOVERY    _CANIOC(10)
 #define CANIOC_SET_NART           _CANIOC(11)
 #define CANIOC_SET_ABOM           _CANIOC(12)
+#define CANIOC_IFLUSH             _CANIOC(13)
+#define CANIOC_OFLUSH             _CANIOC(14)
+#define CANIOC_IOFLUSH            _CANIOC(15)
 
 #define CAN_FIRST                 0x0001         /* First common command */
-#define CAN_NCMDS                 12             /* Ten common commands */
+#define CAN_NCMDS                 15             /* 16 common commands   */
 
 /* User defined ioctl commands are also supported. These will be forwarded
  * by the upper-half CAN driver to the lower-half CAN driver via the