core: Add API to retrieve mtu size

Adding an API to libnetutils to retrieve mtu size of an interface
Made few utility functions from ifc_utils public

Change-Id: Iddec2dcd9f241b146d7f362e2df0724cf740d1f2
(cherry picked from commit 108cded7d96cc347f36b5b78c404c5ebccce13d7)

1 files changed, 19 insertions, 0 deletions

diff --git a/libnetutils/ifc_utils.c b/libnetutils/ifc_utils.c
index a3579a4..1832b92 100644
--- a/libnetutils/ifc_utils.c
+++ b/libnetutils/ifc_utils.c
@@ -1,5 +1,6 @@
 /*
  * Copyright 2008, The Android Open Source Project
+ * Copyright (C) 2011, Code Aurora Forum. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); 
  * you may not use this file except in compliance with the License. 
@@ -981,3 +982,21 @@ int ifc_remove_route(const char *ifname, const char*dst, int prefix_length, cons
 {
     return ifc_act_on_route(SIOCDELRT, ifname, dst, prefix_length, gw);
 }
+
+int ifc_get_mtu(const char *name, int *mtuSz)
+{
+    struct ifreq ifr;
+    ifc_init_ifr(name, &ifr);
+
+    if (mtuSz != NULL) {
+        if(ioctl(ifc_ctl_sock, SIOCGIFMTU, &ifr) < 0) {
+            *mtuSz = 0;
+            return -2;
+        } else {
+            *mtuSz = ifr.ifr_mtu;
+            return 0;
+        }
+    }
+
+    return -1;
+}