Manually added OpenStack API code

[osm/vim-emu.git] / src / emuvim / api / openstack / ip_handler.py

diff --git a/src/emuvim/api/openstack/ip_handler.py b/src/emuvim/api/openstack/ip_handler.py
new file mode 100644 (file)
index 0000000..a03b215
--- /dev/null
+++ b/src/emuvim/api/openstack/ip_handler.py
@@ -0,0 +1,135 @@
+from resources.net import Net
+import threading
+
+lock = threading.Lock()
+
+__issued_ips = dict()
+__default_subnet_size = 256
+__default_subnet_bitmask = 24
+__first_ip = Net.ip_2_int('10.0.0.0')
+__last_ip = Net.ip_2_int('10.255.255.255')
+__current_ip = __first_ip
+
+
+def get_new_cidr(uuid):
+    """
+    Calculates a unused cidr for a subnet.
+
+    :param uuid: The UUID of the subnet - Thus it can store which subnet gets which CIDR
+    :type uuid: ``str``
+    :return: Returns None if all available CIDR are used. Otherwise returns a valid CIDR.
+    :rtype: ``str``
+    """
+    global lock
+    lock.acquire()
+
+    global __current_ip
+    while __first_ip <= __current_ip < __last_ip and __current_ip in __issued_ips:
+        __current_ip += __default_subnet_size
+
+    if __current_ip >= __last_ip or __current_ip < __first_ip or __current_ip in __issued_ips:
+        return None
+
+    __issued_ips[__current_ip] = uuid
+    lock.release()
+
+    return Net.int_2_ip(__current_ip) + '/' + str(__default_subnet_bitmask)
+
+
+def free_cidr(cidr, uuid):
+    """
+    Frees a issued CIDR thus it can be reused.
+
+    :param cidr: The currently used CIDR.
+    :type cidr: ``str``
+    :param uuid: The UUID of the Subnet, which uses this CIDR.
+    :type uuid: ``str``
+    :return: Returns False if the CIDR is None or the UUID did not correspond tho the used CIDR. Else it returns True.
+    :rtype: ``bool``
+    """
+    if cidr is None:
+        return False
+
+    global __current_ip
+    int_ip = Net.cidr_2_int(cidr)
+
+    global lock
+    lock.acquire()
+
+    if int_ip in __issued_ips and __issued_ips[int_ip] == uuid:
+        del __issued_ips[int_ip]
+        if int_ip < __current_ip:
+            __current_ip = int_ip
+        lock.release()
+        return True
+    lock.release()
+    return False
+
+
+def is_cidr_issued(cidr):
+    """
+    Returns True if the CIDR is used.
+
+    :param cidr: The requested CIDR.
+    :type cidr: ``str``
+    :return: Returns True if the CIDR is used, else False.
+    :rtype: ``bool``
+    """
+    if cidr is None:
+        return False
+
+    int_ip = Net.cidr_2_int(cidr)
+
+    if int_ip in __issued_ips:
+        return True
+    return False
+
+
+def is_my_cidr(cidr, uuid):
+    """
+    Checks if the UUID and the used CIDR are related.
+
+    :param cidr: The issued CIDR.
+    :type cidr: ``str``
+    :param uuid: The Subnet UUID.
+    :type uuid: ``str``
+    :return: Returns False if the CIDR is None or if the CIDR is not issued. Else returns True.
+    :rtype: ``bool``
+    """
+    if cidr is None:
+        return False
+
+    int_ip = Net.cidr_2_int(cidr)
+
+    if not int_ip in __issued_ips:
+        return False
+
+    if __issued_ips[int_ip] == uuid:
+        return True
+    return False
+
+
+def assign_cidr(cidr, uuid):
+    """
+    Allows a subnet to request a specific CIDR.
+
+    :param cidr: The requested CIDR.
+    :type cidr: ``str``
+    :param uuid: The Subnet UUID.
+    :type uuid: ``str``
+    :return: Returns False if the CIDR is None or if the CIDR is already issued. Returns True if the CIDR could be
+     assigned to the UUID.
+    """
+    if cidr is None:
+        return False
+
+    int_ip = Net.cidr_2_int(cidr)
+
+    if int_ip in __issued_ips:
+        return False
+
+    global lock
+    lock.acquire()
+    __issued_ips[int_ip] = uuid
+    lock.release()
+    return True