Working around netifaces segfault on FreeBSD

netifaces.gateways() function segmentation fault on FreeBSD, making
Glances unusable. As a workaround, just disable netifaces on FreeBSD.
See https://bitbucket.org/al45tair/netifaces/issues/15.

Fixes #670.

glances/core/glances_autodiscover.py

@@ -35,7 +35,7 @@ except ImportError:
     zeroconf_tag = False
 
 # Import Glances libs
-from glances.core.glances_globals import appname
+from glances.core.glances_globals import appname, is_freebsd
 from glances.core.glances_logging import logger
 
 # Zeroconf 0.17 or higher is needed
@@ -194,13 +194,16 @@ class GlancesAutoDiscoverClient(object):
             except socket.error as e:
                 logger.error("Cannot start zeroconf: {0}".format(e))
 
-            try:
-                # -B @ overwrite the dynamic IPv4 choice
-                if zeroconf_bind_address == '0.0.0.0':
-                    zeroconf_bind_address = self.find_active_ip_address()
-            except KeyError:
-                # Issue #528 (no network interface available)
-                pass
+            # XXX FreeBSD: Segmentation fault (core dumped)
+            # -- https://bitbucket.org/al45tair/netifaces/issues/15
+            if not is_freebsd:
+                try:
+                    # -B @ overwrite the dynamic IPv4 choice
+                    if zeroconf_bind_address == '0.0.0.0':
+                        zeroconf_bind_address = self.find_active_ip_address()
+                except KeyError:
+                    # Issue #528 (no network interface available)
+                    pass
 
             print("Announce the Glances server on the LAN (using {0} IP address)".format(zeroconf_bind_address))
             self.info = ServiceInfo(

glances/core/glances_globals.py

@@ -33,6 +33,7 @@ is_py3 = sys.version_info >= (3, 3)
 # Operating system flag
 # Note: Somes libs depends of OS
 is_bsd = sys.platform.find('bsd') != -1
+is_freebsd = sys.platform.startswith('freebsd')
 is_linux = sys.platform.startswith('linux')
 is_mac = sys.platform.startswith('darwin')
 is_windows = sys.platform.startswith('win')

glances/plugins/glances_ip.py

@@ -19,17 +19,22 @@
 
 """IP plugin."""
 
-# Import system libs
-try:
-    import netifaces
-    netifaces_tag = True
-except ImportError:
-    netifaces_tag = False
-
 # Import Glances libs
+from glances.core.glances_globals import is_freebsd
 from glances.core.glances_logging import logger
 from glances.plugins.glances_plugin import GlancesPlugin
 
+# XXX FreeBSD: Segmentation fault (core dumped)
+# -- https://bitbucket.org/al45tair/netifaces/issues/15
+if not is_freebsd:
+    try:
+        import netifaces
+        netifaces_tag = True
+    except ImportError:
+        netifaces_tag = False
+else:
+    netifaces_tag = False
+
 
 class Plugin(GlancesPlugin):