Fedor Lyanguzov
47 lines
1.4 KiB
Python
47 lines
1.4 KiB
Python
from copy import deepcopy
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from typing import List
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from netaddr import IPNetwork, cidr_merge
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def get_ips(input_file) -> List[IPNetwork]:
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with open(input_file, "r") as file:
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data = file.read().splitlines()
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return [IPNetwork(line) for line in data]
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def reduce_prefixlen(ip: IPNetwork, step=1) -> IPNetwork:
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"""Reduce the CIDR prefix len by step"""
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new_ip = IPNetwork(ip)
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new_ip.prefixlen -= step
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return IPNetwork(new_ip.cidr)
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def merge_ips(ips_to_reduce: List[IPNetwork], max_len, step=1) -> List[IPNetwork]:
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ips = deepcopy(ips_to_reduce)
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reduction_limit_reached = False
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while len(ips) > max_len and not reduction_limit_reached:
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reduced_ips = map(reduce_prefixlen, ips)
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merged_ips = cidr_merge(reduced_ips)
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if len(merged_ips) > 1:
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ips = merged_ips
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else:
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reduction_limit_reached = True
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print("The reduction limit has been reached")
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return ips
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def main():
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file = "cidr4.txt"
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ips = get_ips(file)
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print(f"{len(ips)=}")
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merged_ips = merge_ips(ips, 10)
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print(f"{len(merged_ips)=}")
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print(", ".join([str(x) for x in merged_ips]))
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if __name__ == "__main__":
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assert reduce_prefixlen(IPNetwork("4.78.139.0/24")) == IPNetwork("4.78.138.0/23")
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assert merge_ips(list(map(IPNetwork, ["1.0.0.0/24", "1.0.0.1/24", "1.0.0.2/24"])), 1) == [IPNetwork("1.0.0.0/24")]
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main()
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