From adb677eddd7769743c22adc181a0f4fcd35a6dd6 Mon Sep 17 00:00:00 2001
From: Piotr Jurkiewicz <piotr.jerzy.jurkiewicz@gmail.com>
Date: Tue, 19 Nov 2013 06:50:18 -0800
Subject: [PATCH] bug 1777:  TapBridge address learning patch (modified by Tom
 Goff)

---
 src/tap-bridge/model/tap-bridge.cc | 56 +++++++++++++++++++-----------
 src/tap-bridge/model/tap-bridge.h  |  2 +-
 2 files changed, 37 insertions(+), 21 deletions(-)

diff --git a/src/tap-bridge/model/tap-bridge.cc b/src/tap-bridge/model/tap-bridge.cc
index 83f9c9144..311d55978 100644
--- a/src/tap-bridge/model/tap-bridge.cc
+++ b/src/tap-bridge/model/tap-bridge.cc
@@ -39,29 +39,13 @@
 #include <sys/stat.h>
 #include <sys/socket.h>
 #include <sys/un.h>
+#include <sys/ioctl.h>
+#include <net/if.h>
 #include <cerrno>
 #include <limits>
 #include <cstdlib>
 #include <unistd.h>
 
-//
-// Sometimes having a tap-creator is actually more trouble than solution.  In 
-// these cases you can uncomment the define of TAP_CREATOR below and the 
-// simulation will just use a device you have preconfigured.  This is useful
-// if you are running in an environment where you have got to run as root,
-// such as ORBIT or CORE.
-//
-
-
-// #define NO_CREATOR
-
-#ifdef NO_CREATOR
-#include <fcntl.h>
-#include <net/if.h>
-#include <linux/if_tun.h>
-#include <sys/ioctl.h>
-#endif
-
 NS_LOG_COMPONENT_DEFINE ("TapBridge");
 
 namespace ns3 {
@@ -631,7 +615,7 @@ TapBridge::CreateTap (void)
                   int *rawSocket = (int*)CMSG_DATA (cmsg);
                   NS_LOG_INFO ("Got the socket from the socket creator = " << *rawSocket);
                   m_sock = *rawSocket;
-                  return;
+                  break;
                 }
               else
                 {
@@ -639,8 +623,40 @@ TapBridge::CreateTap (void)
                 }
             }
         }
-      NS_FATAL_ERROR ("Did not get the raw socket from the socket creator");
+      if (cmsg == NULL)
+        {
+          NS_FATAL_ERROR ("Did not get the raw socket from the socket creator");
+        }
+
+      if (m_mode == USE_LOCAL || m_mode == USE_BRIDGE)
+        {
+          //
+          // Set the ns-3 device's mac address to the overlying container's
+          // mac address
+          //
+          struct ifreq s;
+          strncpy (s.ifr_name, m_tapDeviceName.c_str (), sizeof (s.ifr_name));
+
+          NS_LOG_INFO ("Trying to get MacAddr of " << m_tapDeviceName);
+          int ioctlResult = ioctl (sock, SIOCGIFHWADDR, &s);
+          if (ioctlResult == 0)
+            {
+              Mac48Address learnedMac;
+              learnedMac.CopyFrom ((uint8_t *)s.ifr_hwaddr.sa_data);
+              NS_LOG_INFO ("Learned Tap device MacAddr is " << learnedMac << ": setting ns-3 device to use this address");
+              m_bridgedDevice->SetAddress (learnedMac);
+              m_ns3AddressRewritten = true;
+            }
+
+          if (!m_ns3AddressRewritten)
+            {
+              NS_LOG_INFO ("Cannot get MacAddr of Tap device: " << m_tapDeviceName << " while in USE_LOCAL/USE_BRIDGE mode: " << std::strerror (errno));
+              NS_LOG_INFO ("Underlying ns-3 device will continue to use default address, what can lead to connectivity errors");
+            }
+        }
     }
+
+  close (sock);
 }
 
 void
diff --git a/src/tap-bridge/model/tap-bridge.h b/src/tap-bridge/model/tap-bridge.h
index 0d3cc7950..9a3087c45 100644
--- a/src/tap-bridge/model/tap-bridge.h
+++ b/src/tap-bridge/model/tap-bridge.h
@@ -448,7 +448,7 @@ private:
    * \internal
    *
    * Whether the MAC address of the underlying ns-3 device has already been
-   * rewritten is stored in this variable (for UseLocal mode only).
+   * rewritten is stored in this variable (for UseLocal/UseBridge mode only).
    */
   bool m_ns3AddressRewritten;