[PATCH v2 09/11] NetUtils: Adding AddressPool class

[Radek Pazdera]

From: Radek Pazdera <rpazdera(a)redhat.com&gt;

This commit introduces AddressPool class (and its two children -
MacPool and IpPool). This class can be used to generate (and keep
a track of) different types of network addresses within a defined
range.

Signed-off-by: Radek Pazdera <rpazdera(a)redhat.com&gt;
---
 Common/NetUtils.py |   53 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 53 insertions(+), 0 deletions(-)

diff --git a/Common/NetUtils.py b/Common/NetUtils.py
index 42ee6f0..8594a23 100644
--- a/Common/NetUtils.py
+++ b/Common/NetUtils.py
@@ -53,3 +53,56 @@ def get_corespond_local_ip(query_ip):
     if ip is None:
         return ip
     return ip.group(1)
+
+class AddressPool:
+    def __init__(self, start, end):
+        self._next = self._addr_to_byte_string(start)
+        self._final = self._addr_to_byte_string(end)
+
+    def _inc_byte_string(self, byte_string):
+        if len(byte_string):
+            byte_string[-1] += 1
+            if byte_string[-1] > 255:
+                del byte_string[-1]
+                self._inc_byte_string(byte_string)
+                byte_string.append(0)
+
+    def _addr_to_byte_string(self, addr):
+        pass
+
+    def _byte_string_to_addr(self, byte_string):
+        pass
+
+    def get_addr(self):
+        if self._next > self._final:
+            msg = "Pool exhausted, no free addresses available"
+            raise Exception(msg)
+
+        addr_str = self._byte_string_to_addr(self._next)
+        self._inc_byte_string(self._next)
+
+        return addr_str
+
+class MacPool(AddressPool):
+    def _addr_to_byte_string(self, addr):
+        bs = [int(byte, 16) for byte in addr.split(":")]
+
+        if len(bs) != 6:
+            raise Exception("Malformed MAC address")
+
+        return bs
+
+    def _byte_string_to_addr(self, byte_string):
+        return ':'.join(map(lambda x: "%02x" % x, byte_string))
+
+class IpPool(AddressPool):
+    def _addr_to_byte_string(self, addr):
+        bs = [int(byte) for byte in addr.split(".")]
+
+        if len(bs) != 4:
+            raise Exception("Malformed IP address")
+
+        return bs
+
+    def _byte_string_to_addr(self, byte_string):
+        return '.'.join(map(str, byte_string))
-- 
1.7.7.6