Resync helpers for IPv6 support

charm-helpers-sync.yaml

@@ -1,4 +1,4 @@
-branch: lp:charm-helpers
+branch: lp:~james-page/charm-helpers/network-splits
 destination: hooks/charmhelpers
 include:
     - core

hooks/charmhelpers/contrib/network/ip.py

@@ -28,7 +28,7 @@ def _validate_cidr(network):
 
 def get_address_in_network(network, fallback=None, fatal=False):
     """
-    Get an IPv4 address within the network from the host.
+    Get an IPv4 or IPv6 address within the network from the host.
 
     :param network (str): CIDR presentation format. For example,
         '192.168.1.0/24'.
@@ -51,14 +51,23 @@ def get_address_in_network(network, fallback=None, fatal=False):
                 not_found_error_out()
 
     _validate_cidr(network)
+    network = netaddr.IPNetwork(network)
     for iface in netifaces.interfaces():
         addresses = netifaces.ifaddresses(iface)
-        if netifaces.AF_INET in addresses:
+        if network.version == 4 and netifaces.AF_INET in addresses:
             addr = addresses[netifaces.AF_INET][0]['addr']
             netmask = addresses[netifaces.AF_INET][0]['netmask']
             cidr = netaddr.IPNetwork("%s/%s" % (addr, netmask))
-            if cidr in netaddr.IPNetwork(network):
+            if cidr in network:
                 return str(cidr.ip)
+        if network.version == 6 and netifaces.AF_INET6 in addresses:
+            for addr in addresses[netifaces.AF_INET6]:
+                if 'fe80' not in addr['addr']:
+                    netmask = addr['netmask']
+                    cidr = netaddr.IPNetwork("%s/%s" % (addr['addr'],
+                                                        netmask))
+                    if cidr in network:
+                        return str(cidr.ip)
 
     if fallback is not None:
         return fallback
@@ -67,3 +76,97 @@ def get_address_in_network(network, fallback=None, fatal=False):
         not_found_error_out()
 
     return None
+
+
+def is_ipv6(address):
+    '''Determine whether provided address is IPv6 or not'''
+    try:
+        address = netaddr.IPAddress(address)
+    except netaddr.AddrFormatError:
+        # probably a hostname - so not an address at all!
+        return False
+    else:
+        return address.version == 6
+
+
+def is_address_in_network(network, address):
+    """
+    Determine whether the provided address is within a network range.
+
+    :param network (str): CIDR presentation format. For example,
+        '192.168.1.0/24'.
+    :param address: An individual IPv4 or IPv6 address without a net
+        mask or subnet prefix. For example, '192.168.1.1'.
+    :returns boolean: Flag indicating whether address is in network.
+    """
+    try:
+        network = netaddr.IPNetwork(network)
+    except (netaddr.core.AddrFormatError, ValueError):
+        raise ValueError("Network (%s) is not in CIDR presentation format" %
+                         network)
+    try:
+        address = netaddr.IPAddress(address)
+    except (netaddr.core.AddrFormatError, ValueError):
+        raise ValueError("Address (%s) is not in correct presentation format" %
+                         address)
+    if address in network:
+        return True
+    else:
+        return False
+
+
+def _get_for_address(address, key):
+    """Retrieve an attribute of or the physical interface that
+    the IP address provided could be bound to.
+
+    :param address (str): An individual IPv4 or IPv6 address without a net
+        mask or subnet prefix. For example, '192.168.1.1'.
+    :param key: 'iface' for the physical interface name or an attribute
+        of the configured interface, for example 'netmask'.
+    :returns str: Requested attribute or None if address is not bindable.
+    """
+    address = netaddr.IPAddress(address)
+    for iface in netifaces.interfaces():
+        addresses = netifaces.ifaddresses(iface)
+        if address.version == 4 and netifaces.AF_INET in addresses:
+            addr = addresses[netifaces.AF_INET][0]['addr']
+            netmask = addresses[netifaces.AF_INET][0]['netmask']
+            cidr = netaddr.IPNetwork("%s/%s" % (addr, netmask))
+            if address in cidr:
+                if key == 'iface':
+                    return iface
+                else:
+                    return addresses[netifaces.AF_INET][0][key]
+        if address.version == 6 and netifaces.AF_INET6 in addresses:
+            for addr in addresses[netifaces.AF_INET6]:
+                if 'fe80' not in addr['addr']:
+                    cidr = netaddr.IPNetwork("%s/%s" % (addr['addr'],
+                                                        addr['netmask']))
+                    if address in cidr:
+                        if key == 'iface':
+                            return iface
+                        else:
+                            return addr[key]
+    return None
+
+
+def get_iface_for_address(address):
+    """Determine the physical interface to which an IP address could be bound
+
+    :param address (str): An individual IPv4 or IPv6 address without a net
+        mask or subnet prefix. For example, '192.168.1.1'.
+    :returns str: Interface name or None if address is not bindable.
+    """
+    return _get_for_address(address, 'iface')
+
+
+def get_netmask_for_address(address):
+    """Determine the netmask of the physical interface to which and IP address
+    could be bound
+
+    :param address (str): An individual IPv4 or IPv6 address without a net
+        mask or subnet prefix. For example, '192.168.1.1'.
+    :returns str: Netmask of configured interface or None if address is
+        not bindable.
+    """
+    return _get_for_address(address, 'netmask')