-
##############################################################################
# Copyright (c) 2016 Feng Pan (fpan@redhat.com) and others.
#
import ipaddress
+import subprocess
+import re
+import logging
+
+
+def get_ip_range(start_offset=None, count=None, end_offset=None,
+ cidr=None, interface=None):
+ """
+ Generate IP range for a network (cidr) or an interface.
+
+ If CIDR is provided, it will take precedence over interface. In this case,
+ The entire CIDR IP address space is considered usable. start_offset will be
+ calculated from the network address, and end_offset will be calculated from
+ the last address in subnet.
+
+ If interface is provided, the interface IP will be used to calculate
+ offsets:
+ - If the interface IP is in the first half of the address space,
+ start_offset will be calculated from the interface IP, and end_offset
+ will be calculated from end of address space.
+ - If the interface IP is in the second half of the address space,
+ start_offset will be calculated from the network address in the address
+ space, and end_offset will be calculated from the interface IP.
+
+ 2 of start_offset, end_offset and count options must be provided:
+ - If start_offset and end_offset are provided, a range from start_offset
+ to end_offset will be returned.
+ - If count is provided, a range from either start_offset to (start_offset
+ +count) or (end_offset-count) to end_offset will be returned. The
+ IP range returned will be of size <count>.
+ Both start_offset and end_offset must be greater than 0.
+
+ Returns IP range in the format of "first_addr,second_addr" or exception
+ is raised.
+ """
+ if cidr:
+ if count and start_offset and not end_offset:
+ start_index = start_offset
+ end_index = start_offset + count -1
+ elif count and end_offset and not start_offset:
+ end_index = -1 - end_offset
+ start_index = -1 - end_index - count + 1
+ elif start_offset and end_offset and not count:
+ start_index = start_offset
+ end_index = -1 - end_offset
+ else:
+ raise IPUtilsException("Argument error: must pass in exactly 2 of"
+ "start_offset, end_offset and count")
+
+ start_ip = cidr[start_index]
+ end_ip = cidr[end_index]
+ network = cidr
+ elif interface:
+ network = interface.network
+ number_of_addr = network.num_addresses
+ if interface.ip < network[int(number_of_addr / 2)]:
+ if count and start_offset and not end_offset:
+ start_ip = interface.ip + start_offset
+ end_ip = start_ip + count - 1
+ elif count and end_offset and not start_offset:
+ end_ip = network[-1 - end_offset]
+ start_ip = end_ip - count + 1
+ elif start_offset and end_offset and not count:
+ start_ip = interface.ip + start_offset
+ end_ip = network[-1 - end_offset]
+ else:
+ raise IPUtilsException(
+ "Argument error: must pass in exactly 2 of"
+ "start_offset, end_offset and count")
+ else:
+ if count and start_offset and not end_offset:
+ start_ip = network[start_offset]
+ end_ip = start_ip + count -1
+ elif count and end_offset and not start_offset:
+ end_ip = interface.ip - end_offset
+ start_ip = end_ip - count + 1
+ elif start_offset and end_offset and not count:
+ start_ip = network[start_offset]
+ end_ip = interface.ip - end_offset
+ else:
+ raise IPUtilsException(
+ "Argument error: must pass in exactly 2 of"
+ "start_offset, end_offset and count")
+
+ else:
+ raise IPUtilsException("Must pass in cidr or interface to generate"
+ "ip range")
+
+ range_result = _validate_ip_range(start_ip, end_ip, network)
+ if range_result:
+ ip_range = "{},{}".format(start_ip, end_ip)
+ return ip_range
+ else:
+ raise IPUtilsException("Invalid IP range: {},{} for network {}"
+ .format(start_ip, end_ip, network))
+
+
+def get_ip(offset, cidr=None, interface=None):
+ """
+ Returns an IP in a network given an offset.
+
+ Either cidr or interface must be provided, cidr takes precedence.
+
+ If cidr is provided, offset is calculated from network address.
+ If interface is provided, offset is calculated from interface IP.
+
+ offset can be positive or negative, but the resulting IP address must also
+ be contained in the same subnet, otherwise an exception will be raised.
+
+ returns a IP address object.
+ """
+ if cidr:
+ ip = cidr[0 + offset]
+ network = cidr
+ elif interface:
+ ip = interface.ip + offset
+ network = interface.network
+ else:
+ raise IPUtilsException("Must pass in cidr or interface to generate IP")
+
+ if ip not in network:
+ raise IPUtilsException("IP {} not in network {}".format(ip, network))
+ else:
+ return str(ip)
def generate_ip_range(args):
start_position: starting index, default to first address in subnet (1)
end_position: ending index, default to last address in subnet (-1)
- Returns IP range in string format. A single IP is returned if start and end IPs are identical.
+ Returns IP range in string format. A single IP is returned if start and
+ end IPs are identical.
"""
cidr = ipaddress.ip_network(args.CIDR)
(start_index, end_index) = (args.start_position, args.end_position)
return ','.join(sorted([str(cidr[start_index]), str(cidr[end_index])]))
-def main():
- import argparse
- import sys
+def get_interface(nic, address_family=4):
+ """
+ Returns interface object for a given NIC name in the system
+
+ Only global address will be returned at the moment.
+
+ Returns interface object if an address is found for the given nic,
+ otherwise returns None.
+ """
+ if not nic.strip():
+ logging.error("empty nic name specified")
+ return None
+ output = subprocess.getoutput("ip -{} addr show {} scope global"
+ .format(address_family, nic))
+ if address_family == 4:
+ pattern = re.compile("\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}/\d{1,2}")
+ elif address_family == 6:
+ pattern = re.compile("([0-9a-f]{0,4}:){2,7}[0-9a-f]{0,4}/\d{1,3}")
+ else:
+ raise IPUtilsException("Invalid address family: {}"
+ .format(address_family))
+ match = re.search(pattern, output)
+ if match:
+ logging.info("found interface {} ip: {}".format(nic, match.group()))
+ return ipaddress.ip_interface(match.group())
+ else:
+ logging.info("interface ip not found! ip address output:\n{}"
+ .format(output))
+ return None
+
+
+def find_gateway(interface):
+ """
+ Validate gateway on the system
+
+ Ensures that the provided interface object is in fact configured as default
+ route on the system.
+
+ Returns gateway IP (reachable from interface) if default route is found,
+ otherwise returns None.
+ """
+
+ address_family = interface.version
+ output = subprocess.getoutput("ip -{} route".format(address_family))
- parser = argparse.ArgumentParser()
- subparsers = parser.add_subparsers()
+ pattern = re.compile("default\s+via\s+(\S+)\s+")
+ match = re.search(pattern, output)
- parser_gen_ip_range = subparsers.add_parser('generate_ip_range', help='Generate IP Range given CIDR')
- parser_gen_ip_range.add_argument('CIDR', help='Network in CIDR notation')
- parser_gen_ip_range.add_argument('start_position', type=int, help='Starting index')
- parser_gen_ip_range.add_argument('end_position', type=int, help='Ending index')
- parser_gen_ip_range.set_defaults(func=generate_ip_range)
+ if match:
+ gateway_ip = match.group(1)
+ reverse_route_output = subprocess.getoutput("ip route get {}"
+ .format(gateway_ip))
+ pattern = re.compile("{}.+src\s+{}".format(gateway_ip, interface.ip))
+ if not re.search(pattern, reverse_route_output):
+ logging.warning("Default route doesn't match interface specified: "
+ "{}".format(reverse_route_output))
+ return None
+ else:
+ return gateway_ip
+ else:
+ logging.warning("Can't find gateway address on system")
+ return None
+
+
+def _validate_ip_range(start_ip, end_ip, cidr):
+ """
+ Validates an IP range is in good order and the range is part of cidr.
+
+ Returns True if validation succeeds, False otherwise.
+ """
+ ip_range = "{},{}".format(start_ip, end_ip)
+ if end_ip <= start_ip:
+ logging.warning("IP range {} is invalid: end_ip should be greater than "
+ "starting ip".format(ip_range))
+ return False
+ if start_ip not in ipaddress.ip_network(cidr):
+ logging.warning('start_ip {} is not in network {}'
+ .format(start_ip, cidr))
+ return False
+ if end_ip not in ipaddress.ip_network(cidr):
+ logging.warning('end_ip {} is not in network {}'.format(end_ip, cidr))
+ return False
- args = parser.parse_args(sys.argv[1:])
- print(args.func(args))
+ return True
-if __name__ == '__main__':
- main()
+class IPUtilsException(Exception):
+ def __init__(self, value):
+ self.value = value
+ def __str__(self):
+ return self.value
Code Review / apex.git / blobdiff