From fb240b8d5d01ea6587eb7355c33c9a96aa18942f Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Thu, 20 Mar 2014 17:27:59 -0600
Subject: net/netdev_findbyaddr.c:  Skip network devices that are in the down
 state.  They have no meaning address

---
 nuttx/net/netdev_findbyaddr.c | 32 ++++++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 6 deletions(-)

(limited to 'nuttx/net/netdev_findbyaddr.c')

diff --git a/nuttx/net/netdev_findbyaddr.c b/nuttx/net/netdev_findbyaddr.c
index 8ca1ae3b2..dbfea28cc 100644
--- a/nuttx/net/netdev_findbyaddr.c
+++ b/nuttx/net/netdev_findbyaddr.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/netdev_findbyaddr.c
  *
- *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -55,7 +55,7 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Priviate Types
+ * Private Types
  ****************************************************************************/
 
 /****************************************************************************
@@ -79,7 +79,8 @@
  *
  * Description:
  *   Find a previously registered network device by matching a local address
- *   with the subnet served by the device
+ *   with the subnet served by the device.  Only "up" devices are considered
+ *   (since a "down" device has no meaningful address).
  *
  * Parameters:
  *   addr - Pointer to the remote address of a connection
@@ -95,17 +96,36 @@
 static FAR struct uip_driver_s *netdev_finddevice(const uip_ipaddr_t addr)
 {
   struct uip_driver_s *dev;
+  uint8_t iff;
+
+  /* Examine each registered network device */
 
   netdev_semtake();
   for (dev = g_netdevices; dev; dev = dev->flink)
     {
-      if (uip_ipaddr_maskcmp(dev->d_ipaddr, addr, dev->d_netmask))
+      /* Get the interface flags */
+
+      if (uip_getifstatus(dev->d_ifname, &iff) == OK)
         {
-          netdev_semgive();
-          return dev;
+          /* Is the interface in the "up" state? */
+
+          if ((iff & IFF_UP) != 0)
+            {
+              /* Yes.. check for an address match (under the netmask) */
+
+              if (uip_ipaddr_maskcmp(dev->d_ipaddr, addr, dev->d_netmask))
+                {
+                  /* Its a match */
+
+                  netdev_semgive();
+                  return dev;
+                }
+            }
         }
     }
 
+  /* No device with the matching address found */
+
   netdev_semgive();
   return NULL;
 }
-- 
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