Add trivial net device statistics (TX and RX packet count), reported

via UNDI API and also by ifstat command; may be useful for debugging.

src/include/gpxe/netdevice.h

 	const uint8_t *ll_broadcast;
 };
 
+/**
+ * Network device statistics
+ *
+ */
+struct net_device_stats {
+	/** Count of successfully completed transmissions */
+	unsigned int tx_count;
+	/** Count of successfully received packets */
+	unsigned int rx_count;
+};
+
 /**
  * A network device
  *
 	struct list_head tx_queue;
 	/** RX packet queue */
 	struct list_head rx_queue;
+	/** Device statistics */
+	struct net_device_stats stats;
 
 	/** Driver private data */
 	void *priv;

src/interface/pxe/pxe_undi.c

 
 /* PXENV_UNDI_GET_STATISTICS
  *
- * Status: won't implement (would require driver API changes for no
- * real benefit)
+ * Status: working
  */
 PXENV_EXIT_t pxenv_undi_get_statistics ( struct s_PXENV_UNDI_GET_STATISTICS
 					 *undi_get_statistics ) {
 	DBG ( "PXENV_UNDI_GET_STATISTICS" );
 
-	undi_get_statistics->Status = PXENV_STATUS_UNSUPPORTED;
-	return PXENV_EXIT_FAILURE;
+	undi_get_statistics->XmtGoodFrames = pxe_netdev->stats.tx_count;
+	undi_get_statistics->RcvGoodFrames = pxe_netdev->stats.rx_count;
+	undi_get_statistics->RcvCRCErrors = 0;
+	undi_get_statistics->RcvResourceErrors = 0;
+
+	undi_get_statistics->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
 }
 
 /* PXENV_UNDI_CLEAR_STATISTICS
  *
- * Status: won't implement (would require driver API changes for no
- * real benefit)
+ * Status: working
  */
 PXENV_EXIT_t pxenv_undi_clear_statistics ( struct s_PXENV_UNDI_CLEAR_STATISTICS
 					   *undi_clear_statistics ) {
 	DBG ( "PXENV_UNDI_CLEAR_STATISTICS" );
 
-	undi_clear_statistics->Status = PXENV_STATUS_UNSUPPORTED;
-	return PXENV_EXIT_FAILURE;
+	memset ( &pxe_netdev->stats, 0, sizeof ( pxe_netdev->stats ) );
+
+	undi_clear_statistics->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
 }
 
 /* PXENV_UNDI_INITIATE_DIAGS

src/net/netdevice.c

 	assert ( iobuf->list.next != NULL );
 	assert ( iobuf->list.prev != NULL );
 
+	/* Dequeue and free I/O buffer */
 	list_del ( &iobuf->list );
 	free_iob ( iobuf );
+
+	/* Update statistics counter */
+	netdev->stats.tx_count++;
 }
 
 /**
 void netdev_rx ( struct net_device *netdev, struct io_buffer *iobuf ) {
 	DBGC ( netdev, "NETDEV %p received %p (%p+%zx)\n",
 	       netdev, iobuf, iobuf->data, iob_len ( iobuf ) );
+
+	/* Enqueue packet */
 	list_add_tail ( &iobuf->list, &netdev->rx_queue );
+
+	/* Update statistics counter */
+	netdev->stats.rx_count++;
 }
 
 /**

src/usr/ifmgmt.c

  * @v netdev		Network device
  */
 void ifstat ( struct net_device *netdev ) {
-	printf ( "%s: %s on %s (%s)\n",
+	printf ( "%s: %s on %s (%s) TX:%d RX:%d\n",
 		 netdev->name, netdev_hwaddr ( netdev ), netdev->dev->name,
-		 ( ( netdev->state & NETDEV_OPEN ) ? "open" : "closed" ) );
+		 ( ( netdev->state & NETDEV_OPEN ) ? "open" : "closed" ),
+		 netdev->stats.tx_count, netdev->stats.rx_count );
 }