Php 计算给定网络中可用子网的数量

在计算网络中可用子网（或主机）的数量时，我有以下问题。例如，主子网是/24（255.255.255.0），其中包含两个/25（255.255.255.128）或四个/26（255.255.255.192）

因此，如果一个节点已经被使用，那么只有1/25或3次/26。那么我应该如何计算可用子网的数量。换句话说，如何获得余数的数量和类型。 我想在PHP中执行这个算法。

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我使用python解决了这个问题（所有代码都附在后面，最后是整个脚本），但我确信PHP也存在类似的解决方案库。由于这是一个很老的解决方案，而且没有发布任何解决方案，我猜任何解决方案（在本例中是Python解决方案）都比没有解决方案好

该脚本由两个函数组成，一个函数使用计算“主”子网内的可用子网，另一个函数使用创建pdf图形

我使用的算法是一个非常简单的BFS。它基本上从顶部子网（“main”和/24）开始，并找出是否有任何使用的（“take”）子网与它重叠/匹配。如果它们中有任何一个这样做了，算法会将它的“子项”（/25）排成队列，以便在同一过程中进行检查。如果算法命中的子网没有“take”子网，则该子网将标记为“available”。如果它访问的子网与“take”完全匹配，则会将其标记为“take”。在任何其他情况下，迭代都将继续

可视化的绘图过程是相同的

以下是脚本说明（argparse生成）：

使用您的参数运行脚本：

subnet_script.py -m 255.255.255.0/24 -t 255.255.255.192/26 -o test

给出了以下结果：

做一些更有趣的事情，比如：

script.py -m 255.255.255.0/24 -t 255.255.255.192/26 255.255.255.128/30 -o test

给出了以下结果：

我使用了、和（对于python）模块，并使脚本更易于使用

第一个功能：

def get_available_subnets_set(main, taken):
    # we assume no subnets are available intially
    available = []
    q = queue.Queue()
    # add first node for expansion in the BFS process
    q.put(main)

    while q.qsize() > 0:
        subnet = q.get()
        for taken_subnet in taken:
            if taken_subnet.compare_networks(subnet) == 0:
                # found matching subnet in taken, stop expanding
                print("similar: %s and %s" % (subnet, taken_subnet))
                break
            if taken_subnet.overlaps(subnet):
                # still has overlaps somewhere in children, keep expanding
                print("overlaps: %s and %s" % (subnet, taken_subnet))
                for sub_subnet in subnet.subnets():
                    q.put(sub_subnet)
                break
        else:
            # no overlaps with taken - this subnet is entirely available
            available.append(subnet)

    return set(available)

第二个函数以类似的方式使用graphviz绘制结果：

def make_subnet_graph(main, taken_subnets, available_subnets, filename):

    g = graphviz.Graph()
    q = queue.Queue()
    q.put(main)
    g.node(str(main))

    while q.qsize() > 0:
        subnet = q.get()
        for sub_subnet in subnet.subnets():
            if sub_subnet in available_subnets:
                # draw as available (green)
                g.node(str(sub_subnet), _attributes={"color": "green"})
                g.edge(str(sub_subnet), str(subnet))
                continue
            if sub_subnet in taken_subnets:
                # draw as taken (red)
                g.node(str(sub_subnet), _attributes={"color": "red"})
                g.edge(str(sub_subnet), str(subnet))
                continue

            # has mixed type subnets (taken / available) - go deeper
            g.node(str(sub_subnet))
            g.edge(str(sub_subnet), str(subnet))
            q.put(sub_subnet)

    # write file
    g.render(filename)

整个过程与argparse一起：

#!/usr/bin/env python3.4

import ipaddress
import argparse
import queue
import graphviz


def get_available_subnets(main, taken):
    # we assume no subnets are available intially
    available = []
    q = queue.Queue()
    # add first node for expansion in the BFS process
    q.put(main)

    while q.qsize() > 0:
        subnet = q.get()
        for taken_subnet in taken:
            if taken_subnet.compare_networks(subnet) == 0:
                # found matching subnet in taken, stop expanding
                print("similar: %s and %s" % (subnet, taken_subnet))
                break
            if taken_subnet.overlaps(subnet):
                # still has overlaps somewhere in children, keep expanding
                print("overlaps: %s and %s" % (subnet, taken_subnet))
                for sub_subnet in subnet.subnets():
                    q.put(sub_subnet)
                break
        else:
            # no overlaps with taken - this subnet is entirely available
            available.append(subnet)

    return available

def make_subnet_graph(main, taken_subnets, available_subnets, filename):

    g = graphviz.Graph()
    q = queue.Queue()
    q.put(main)
    g.node(str(main))

    while q.qsize() > 0:
        subnet = q.get()
        for sub_subnet in subnet.subnets():
            if sub_subnet in available_subnets:
                # draw as available (green)
                g.node(str(sub_subnet), _attributes={"color": "green"})
                g.edge(str(sub_subnet), str(subnet))
                continue
            if sub_subnet in taken_subnets:
                # draw as taken (red)
                g.node(str(sub_subnet), _attributes={"color": "red"})
                g.edge(str(sub_subnet), str(subnet))
                continue

            # has mixed type subnets (taken / available) - go deeper
            g.node(str(sub_subnet))
            g.edge(str(sub_subnet), str(subnet))
            q.put(sub_subnet)

    # write file
    g.render(filename)


if "__main__" == __name__:
    parser = argparse.ArgumentParser()
    parser.add_argument('-m', '--m', help='main subnet to check', required=True)
    parser.add_argument('-t', '--taken', nargs='+', help='taken subnets', required=True)
    parser.add_argument('-o', '--output', help='graphviz output file name (.pdf)', required=True)
    args = parser.parse_args()

    taken = [ipaddress.IPv4Network(subnet) for subnet in args.taken]
    main = ipaddress.IPv4Network(args.m)
    available = get_available_subnets_set(main, taken)

    make_subnet_graph(main, taken, available, args.output)

#!/usr/bin/env python3.4

import ipaddress
import argparse
import queue
import graphviz


def get_available_subnets(main, taken):
    # we assume no subnets are available intially
    available = []
    q = queue.Queue()
    # add first node for expansion in the BFS process
    q.put(main)

    while q.qsize() > 0:
        subnet = q.get()
        for taken_subnet in taken:
            if taken_subnet.compare_networks(subnet) == 0:
                # found matching subnet in taken, stop expanding
                print("similar: %s and %s" % (subnet, taken_subnet))
                break
            if taken_subnet.overlaps(subnet):
                # still has overlaps somewhere in children, keep expanding
                print("overlaps: %s and %s" % (subnet, taken_subnet))
                for sub_subnet in subnet.subnets():
                    q.put(sub_subnet)
                break
        else:
            # no overlaps with taken - this subnet is entirely available
            available.append(subnet)

    return available

def make_subnet_graph(main, taken_subnets, available_subnets, filename):

    g = graphviz.Graph()
    q = queue.Queue()
    q.put(main)
    g.node(str(main))

    while q.qsize() > 0:
        subnet = q.get()
        for sub_subnet in subnet.subnets():
            if sub_subnet in available_subnets:
                # draw as available (green)
                g.node(str(sub_subnet), _attributes={"color": "green"})
                g.edge(str(sub_subnet), str(subnet))
                continue
            if sub_subnet in taken_subnets:
                # draw as taken (red)
                g.node(str(sub_subnet), _attributes={"color": "red"})
                g.edge(str(sub_subnet), str(subnet))
                continue

            # has mixed type subnets (taken / available) - go deeper
            g.node(str(sub_subnet))
            g.edge(str(sub_subnet), str(subnet))
            q.put(sub_subnet)

    # write file
    g.render(filename)


if "__main__" == __name__:
    parser = argparse.ArgumentParser()
    parser.add_argument('-m', '--m', help='main subnet to check', required=True)
    parser.add_argument('-t', '--taken', nargs='+', help='taken subnets', required=True)
    parser.add_argument('-o', '--output', help='graphviz output file name (.pdf)', required=True)
    args = parser.parse_args()

    taken = [ipaddress.IPv4Network(subnet) for subnet in args.taken]
    main = ipaddress.IPv4Network(args.m)
    available = get_available_subnets_set(main, taken)

    make_subnet_graph(main, taken, available, args.output)