From aaf59e60505be5292f4d11cafe5a853eac1d8185 Mon Sep 17 00:00:00 2001
From: grossmj <grossmj@gns3.net>
Date: Thu, 15 Mar 2018 17:20:40 +0700
Subject: [PATCH] Allow to configure the interface to be used by the NAT node.
 Fixes #1175.

---
 conf/gns3_server.conf                   |  7 ++++++-
 gns3server/compute/builtin/nodes/nat.py | 20 +++++++++++++-------
 2 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/conf/gns3_server.conf b/conf/gns3_server.conf
index 5971376c..5e36fb31 100644
--- a/conf/gns3_server.conf
+++ b/conf/gns3_server.conf
@@ -40,7 +40,12 @@ user = gns3
 password = gns3
 
 ; Only allow these interfaces to be used by GNS3, for the Cloud node for example (Linux/OSX only)
-allowed_interfaces = eth0,eth1
+; Do not forget to allow virbr0 in order for the NAT node to work
+allowed_interfaces = eth0,eth1,virbr0
+
+; Specify the NAT interface to be used by the NAT node
+; Default is virbr0 on Linux (requires libvirt) and vmnet8 for other platforms (requires VMware)
+nat_interface = vmnet10
 
 [VPCS]
 ; VPCS executable location, default: search in PATH
diff --git a/gns3server/compute/builtin/nodes/nat.py b/gns3server/compute/builtin/nodes/nat.py
index b8782ed2..2e745177 100644
--- a/gns3server/compute/builtin/nodes/nat.py
+++ b/gns3server/compute/builtin/nodes/nat.py
@@ -22,6 +22,9 @@ from ...error import NodeError
 
 import gns3server.utils.interfaces
 
+import logging
+log = logging.getLogger(__name__)
+
 
 class Nat(Cloud):
     """
@@ -29,19 +32,22 @@ class Nat(Cloud):
     NAT access.
     """
 
-    def __init__(self, *args, **kwargs):
+    def __init__(self, name, node_id, project, manager, ports=None):
 
         if sys.platform.startswith("linux"):
-            if "virbr0" not in [interface["name"] for interface in gns3server.utils.interfaces.interfaces()]:
-                raise NodeError("virbr0 is missing, please install libvirt")
-            interface = "virbr0"
+            nat_interface = manager.config.get_section_config("Server").get("nat_interface", "virbr0")
+            if nat_interface not in [interface["name"] for interface in gns3server.utils.interfaces.interfaces()]:
+                raise NodeError("NAT interface {} is missing, please install libvirt".format(nat_interface))
+            interface = nat_interface
         else:
-            interfaces = list(filter(lambda x: 'vmnet8' in x.lower(),
+            nat_interface = manager.config.get_section_config("Server").get("nat_interface", "vmnet8")
+            interfaces = list(filter(lambda x: nat_interface in x.lower(),
                            [interface["name"] for interface in gns3server.utils.interfaces.interfaces()]))
             if not len(interfaces):
-                raise NodeError("vmnet8 is missing. You need to install VMware or use the NAT node on GNS3 VM")
+                raise NodeError("NAT interface {} is missing. You need to install VMware or use the NAT node on GNS3 VM".format(nat_interface))
             interface = interfaces[0]  # take the first available interface containing the vmnet8 name
 
+        log.info("NAT node '{}' configured to use NAT interface '{}'".format(name, interface))
         ports = [
             {
                 "name": "nat0",
@@ -50,7 +56,7 @@ class Nat(Cloud):
                 "port_number": 0
             }
         ]
-        super().__init__(*args, ports=ports)
+        super().__init__(name, node_id, project, manager, ports=ports)
 
     @property
     def ports_mapping(self):