[Common] Add is_interface to validate network interfaces

Libtorrent now supports interface names instead of just IP address so
add new common functions to validate user input.

* Added is_interface that will verify if a libtorrent interface of name
or IP address.
* Added is_interface_name to verify that the name supplied is a valid
network interface name in the operating system.
  On Windows sock.if_nameindex() is only supported on 3.8+ and does not
return a uuid (required by libtorrent) so use ifaddr package. Using git
commit version for ifaddr due to adapter name decode bug in v0.1.7.
On other OSes attempt to use stdlib and fallback to ifaddr if installed
otherwiser return True.
* Added tests for is_interface & is_interface_name
* Updated UIs with change from address to interface
* Updated is_ipv6 and is_ipv4 to used inet_pton; now supported on
Windows.

Ref: https://github.com/pydron/ifaddr/pull/32
Closes: https://github.com/deluge-torrent/deluge/pull/338

1 files changed, 73 insertions, 19 deletions

diff --git a/deluge/common.py b/deluge/common.py
index da056d484..82adb0715 100644
--- a/deluge/common.py
+++ b/deluge/common.py
@@ -17,6 +17,7 @@ import numbers
 import os
 import platform
 import re
+import socket
 import subprocess
 import sys
 import tarfile
@@ -44,6 +45,11 @@ if platform.system() in ('Windows', 'Microsoft'):
 
     os.environ['SSL_CERT_FILE'] = where()
 
+try:
+    import ifaddr
+except ImportError:
+    ifaddr = None
+
 
 if platform.system() not in ('Windows', 'Microsoft', 'Darwin'):
     # gi makes dbus available on Window but don't import it as unused.
@@ -900,6 +906,29 @@ def free_space(path):
         return disk_data.f_bavail * block_size
 
 
+def is_interface(interface):
+    """Check if interface is a valid IP or network adapter.
+
+    Args:
+        interface (str): The IP or interface name to test.
+
+    Returns:
+        bool: Whether interface is valid is not.
+
+    Examples:
+        Windows:
+        >>> is_interface('{7A30AE62-23ZA-3744-Z844-A5B042524871}')
+        >>> is_interface('127.0.0.1')
+        True
+        Linux:
+        >>> is_interface('lo')
+        >>> is_interface('127.0.0.1')
+        True
+
+    """
+    return is_ip(interface) or is_interface_name(interface)
+
+
 def is_ip(ip):
     """A test to see if 'ip' is a valid IPv4 or IPv6 address.
 
@@ -935,15 +964,12 @@ def is_ipv4(ip):
 
     """
 
-    import socket
-
     try:
-        if windows_check():
-            return socket.inet_aton(ip)
-        else:
-            return socket.inet_pton(socket.AF_INET, ip)
+        socket.inet_pton(socket.AF_INET, ip)
     except OSError:
         return False
+    else:
+        return True
 
 
 def is_ipv6(ip):
@@ -962,23 +988,51 @@ def is_ipv6(ip):
     """
 
     try:
-        import ipaddress
-    except ImportError:
-        import socket
-
-        try:
-            return socket.inet_pton(socket.AF_INET6, ip)
-        except (OSError, AttributeError):
-            if windows_check():
-                log.warning('Unable to verify IPv6 Address on Windows.')
-                return True
+        socket.inet_pton(socket.AF_INET6, ip)
+    except OSError:
+        return False
     else:
+        return True
+
+
+def is_interface_name(name):
+    """Returns True if an interface name exists.
+
+    Args:
+        name (str): The Interface to test. eg. eth0 linux. GUID on Windows.
+
+    Returns:
+        bool: Whether name is valid or not.
+
+    Examples:
+        >>> is_interface_name("eth0")
+        True
+        >>> is_interface_name("{7A30AE62-23ZA-3744-Z844-A5B042524871}")
+        True
+
+    """
+
+    if not windows_check():
         try:
-            return ipaddress.IPv6Address(decode_bytes(ip))
-        except ipaddress.AddressValueError:
+            socket.if_nametoindex(name)
+        except OSError:
             pass
+        else:
+            return True
+
+    if ifaddr:
+        try:
+            adapters = ifaddr.get_adapters()
+        except OSError:
+            return True
+        else:
+            return any([name == a.name for a in adapters])
+
+    if windows_check():
+        regex = '^{[0-9A-Z]{8}-([0-9A-Z]{4}-){3}[0-9A-Z]{12}}$'
+        return bool(re.search(regex, str(name)))
 
-    return False
+    return True
 
 
 def decode_bytes(byte_str, encoding='utf8'):