Php 测试cidr表示法中的一个网络是否与另一个网络重叠_Php_Ipv4_Cidr

Php 测试cidr表示法中的一个网络是否与另一个网络重叠

php

Php 测试cidr表示法中的一个网络是否与另一个网络重叠,php,ipv4,cidr,Php,Ipv4,Cidr,我正在寻找一种php算法，它可以有效地测试一个cidr标记的网络是否与另一个重叠我基本上有以下情况： cidr地址数组： $cidrNetworks = array( '192.168.10.0/24', '10.10.0.30/20', etc. ); 我有一个方法可以将网络添加到数组中，但是当添加的网络与数组中的网络allready重叠时，该方法应该引发异常因此，如果添加了192.168.10.0/25，则应引发异常有没有人有/知道/能想到一种有效测试这一点的

我正在寻找一种php算法，它可以有效地测试一个cidr标记的网络是否与另一个重叠

我基本上有以下情况：

cidr地址数组：

$cidrNetworks = array(
    '192.168.10.0/24',
    '10.10.0.30/20',
    etc.
);

我有一个方法可以将网络添加到数组中，但是当添加的网络与数组中的网络allready重叠时，该方法应该引发异常

因此，如果添加了192.168.10.0/25，则应引发异常

有没有人有/知道/能想到一种有效测试这一点的方法

凭直觉，我建议你做如下事情：

让新条目为

将

转换为单个整数形式，让该整数为

让任何条目的掩码长度

mask（A）

比较

mask（条目）=mask（Y）

屏蔽

Mask（entry）>Mask（Y）

中的现有条目，并与

为每个现有条目关闭

，其中

Mask（entry）

，以便Mask（Y）=Mask（entry）
并进行比较


只要你没有遇到碰撞，一切都很好
当然，这不会检查建议的子网是否有效
我在这里的正确性主张是，我想不出一个反例，但很可能有一个反例，所以我提供这个作为进一步思考的基础-希望这有帮助。
正如PHP chat中简要讨论的，下面是我将如何实现它，以比较任意两个地址
将IP地址转换为二进制形式
从CIDR格式中提取掩码
取两个面具中最小的一个（最不具体）=
（包含更多地址）
在两个二进制表示上使用掩码
比较两者
如果存在匹配项，则一个包含在另一个中
下面是一些示例代码，它不是很漂亮，您需要对其进行调整以适应您的阵列
function bin_pad($num)
{
    return str_pad(decbin($num), 8, '0', STR_PAD_LEFT);
}

$ip1 = '192.168.0.0/23';
$ip2 = '192.168.1.0/24';

$regex = '~(\d+)\.(\d+)\.(\d+)\.(\d+)/(\d+)~';

preg_match($regex, $ip1, $ip1);
preg_match($regex, $ip2, $ip2);

$mask = min($ip1[5], $ip2[5]);

$ip1 = substr(
    bin_pad($ip1[1]) . bin_pad($ip1[2]) .
    bin_pad($ip1[3]) . bin_pad($ip1[4]),
    0, $mask
);

$ip2 = substr(
    bin_pad($ip2[1]) . bin_pad($ip2[2]) .
    bin_pad($ip2[3]) . bin_pad($ip2[4]),
    0, $mask
);

var_dump($ip1, $ip2, $ip1 === $ip2);

我很难使它兼容32位，这就是为什么我最终选择将IP地址的每个八位字节分别转换为二进制，然后使用substr

我一开始使用的是pack（'C4'，$ip[1]..$ip[4]）
，但当涉及到使用完整的32位掩码时，我在将其转换为二进制时遇到了问题（因为PHP整数是有符号的）。但考虑到了未来的实现
 
<?php
    function checkOverlap ($net1, $net2) {

        $mask1 = explode("/", $net1)[1];
        $net1 = explode("/", $net1)[0];
        $netArr1 = explode(".",$net1);

        $mask2 = explode("/", $net2)[1];
        $net2 = explode("/", $net2)[0];
        $netArr2 = explode(".",$net2);

        $newnet1 = $newnet2 = "";

        foreach($netArr1 as $num) {
            $binnum = decbin($num);
            $length = strlen($binnum);
            for ($i = 0; $i < 8-$length; $i++) {
                $binnum = '0'.$binnum;
            }
            $newnet1 .= $binnum;
        }

        foreach($netArr2 as $num) {
            $binnum = decbin($num);
            $length = strlen($binnum);
            for ($i = 0; $i < 8-$length; $i++) {
                $binnum = '0'.$binnum;
            }
            $newnet2 .= $binnum;
        }

        $length = min($mask1, $mask2);

        $newnet1 = substr($newnet1,0,$length);
        $newnet2 = substr($newnet2,0,$length);

        $overlap = 0;
        if ($newnet1 == $newnet2) $overlap = 1;

        return $overlap;
    }

    function networksOverlap ($networks, $newnet) {

        $overlap = false;

        foreach ($networks as $network) {
            $overlap = checkOverlap($network, $newnet);
            if ($overlap) return 1;
        }

        return $overlap;        

    }

    $cidrNetworks = array(
        '192.168.10.0/24',
        '10.10.0.30/20'
    );

    $newnet = "192.168.10.0/25";

    $overlap = networksOverlap($cidrNetworks, $newnet);
?>


不确定这是否100%正确，但请尝试一下，看看是否有效。
这是之前在chat中讨论的类的更新版本。它可以做你需要的，以及许多其他有用的事情
<?php

    class IPv4Subnet implements ArrayAccess, Iterator {

        /*
         * Address format constants
         */
        const ADDRESS_BINARY = 0x01;
        const ADDRESS_INT = 0x02;
        const ADDRESS_DOTDEC = 0x04;
        const ADDRESS_SUBNET = 0x08;

        /*
         * Constants to control whether getHosts() returns the network/broadcast addresses
         */
        const HOSTS_WITH_NETWORK = 0x10;
        const HOSTS_WITH_BROADCAST = 0x20;
        const HOSTS_ALL = 0x30;

        /*
         * Properties to store base address and subnet mask as binary strings
         */
        protected $address;
        protected $mask;

        /*
         * Counter to track the current iteration offset
         */
        private $iteratorOffset = 0;

        /*
         * Array to hold values retrieved via ArrayAccess
         */
        private $arrayAccessObjects = array();

        /*
         * Helper methods
         */
        private function longToBinary ($long) {
            return pack('N', $long);
        }
        private function longToDottedDecimal ($long) {
            return ($long >> 24 & 0xFF).'.'.($long >> 16 & 0xFF).'.'.($long >> 8 & 0xFF).'.'.($long & 0xFF);
        }
        private function longToByteArray ($long) {
            return array(
                $long >> 24 & 0xFF,
                $long >> 16 & 0xFF,
                $long >> 8 & 0xFF,
                $long & 0xFF
            );
        }
        private function longToSubnet ($long) {
            if (!isset($this->arrayAccessObjects[$long])) {
                $this->arrayAccessObjects[$long] = new self($long);
            }
            return $this->arrayAccessObjects[$long];
        }
        private function binaryToLong ($binary) {
            return current(unpack('N', $binary));
        }
        private function binaryToDottedDecimal ($binary) {
            return implode('.', unpack('C*', $binary));
        }
        private function binaryToX ($binary, $mode) {
            if ($mode & self::ADDRESS_BINARY) {
                $result = $binary;
            } else if ($mode & self::ADDRESS_INT) {
                $result = $this->binaryToLong($binary);
            } else if ($mode & self::ADDRESS_DOTDEC) {
                $result = $this->binaryToDottedDecimal($binary);
            } else {
                $result = $this->longToSubnet($this->binaryToLong($binary));
            }
            return $result;
        }
        private function byteArrayToLong($bytes) {
            return ($bytes[0] << 24) | ($bytes[1] << 16) | ($bytes[2] << 8) | $bytes[3];
        }
        private function byteArrayToBinary($bytes) {
            return pack('C*', $bytes[0], $bytes[1], $bytes[2], $bytes[3]);
        }

        private function normaliseComparisonSubject (&$subject) {
            if (!is_object($subject)) {
                $subject = new self($subject);
            }
            if (!($subject instanceof self)) {
                throw new InvalidArgumentException('Subject must be an instance of IPv4Subnet');
            }
        }

        private function validateOctetArray (&$octets) {
            foreach ($octets as &$octet) {
                $octet = (int) $octet;
                if ($octet < 0 || $octet > 255) {
                    return FALSE;
                }
            }
            return TRUE;
        }

        /*
         * Constructor
         */
        public function __construct ($address = NULL, $mask = NULL) {
            if ($address === NULL || (is_string($address) && trim($address) === '')) {
                $address = array(0, 0, 0, 0);
            } else if (is_int($address)) {
                $address = $this->longToByteArray($address);
            } else if (is_string($address)) {
                $parts = preg_split('#\s*/\s*#', trim($address), -1, PREG_SPLIT_NO_EMPTY);
                if (count($parts) > 2) {
                    throw new InvalidArgumentException('No usable IP address supplied: Syntax error');
                } else if ($parts[0] === '') {
                    throw new InvalidArgumentException('No usable IP address supplied: IP address empty');
                }
                if (!empty($parts[1]) && !isset($mask)) {
                    $mask = $parts[1];
                }
                $address = preg_split('#\s*\.\s*#', $parts[0], -1, PREG_SPLIT_NO_EMPTY);
            } else if (is_array($address)) {
                $address = array_values($address);
            } else {
                throw new InvalidArgumentException('No usable IP address supplied: Value must be a string or an integer');
            }

            $suppliedAddressOctets = count($address);
            $address += array(0, 0, 0, 0);
            if ($suppliedAddressOctets > 4) {
                throw new InvalidArgumentException('No usable IP address supplied: IP address has more than 4 octets');
            } else if (!$this->validateOctetArray($address)) {
                throw new InvalidArgumentException('No usable IP address supplied: At least one octet value outside acceptable range 0 - 255');
            }

            if ($mask === NULL) {
                $mask = array_pad(array(), $suppliedAddressOctets, 255) + array(0, 0, 0, 0);
            } else if (is_int($mask)) {
                $mask = $this->longToByteArray($mask);
            } else if (is_string($mask)) {
                $mask = preg_split('#\s*\.\s*#', trim($mask), -1, PREG_SPLIT_NO_EMPTY);

                switch (count($mask)) {
                    case 1: // CIDR
                        $cidr = (int) $mask[0];
                        if ($cidr === 0) {
                            // Shifting 32 bits on a 32 bit system doesn't work, so treat this as a special case
                            $mask = array(0, 0, 0, 0);
                        } else if ($cidr <= 32) {
                            // This looks odd, but it's the nicest way I have found to get the 32 least significant bits set in a
                            // way that works on both 32 and 64 bit platforms
                            $base = ~((~0 << 16) << 16);
                            $mask = $this->longToByteArray($base << (32 - $cidr));
                        } else {
                            throw new InvalidArgumentException('Supplied mask invalid: CIDR outside acceptable range 0 - 32');
                        }
                        break;
                    case 4: break; // Dotted decimal
                    default: throw new InvalidArgumentException('Supplied mask invalid: Must be either a full dotted-decimal or a CIDR');
                }
            } else if (is_array($mask)) {
                $mask = array_values($mask);
            } else {
                throw new InvalidArgumentException('Supplied mask invalid: Type invalid');
            }

            if (!$this->validateOctetArray($mask)) {
                throw new InvalidArgumentException('Supplied mask invalid: At least one octet value outside acceptable range 0 - 255');
            }
            // Check bits are contiguous from left
            // TODO: Improve this mechanism
            $asciiBits = sprintf('%032b', $this->byteArrayToLong($mask));
            if (strpos(rtrim($asciiBits, '0'), '0') !== FALSE) {
                throw new InvalidArgumentException('Supplied mask invalid: Set bits are not contiguous from the most significant bit');
            }

            $this->mask = $this->byteArrayToBinary($mask);
            $this->address = $this->byteArrayToBinary($address) & $this->mask;
        }

        /*
         * ArrayAccess interface methods (read only)
         */
        public function offsetExists ($offset) {
            if ($offset === 'network' || $offset === 'broadcast') {
                return TRUE;
            }

            $offset = filter_var($offset, FILTER_VALIDATE_INT);
            if ($offset === FALSE || $offset < 0) {
                return FALSE;
            }

            return $offset < $this->getHostsCount();
        }
        public function offsetGet ($offset) {
            if (!$this->offsetExists($offset)) {
                return NULL;
            }

            if ($offset === 'network') {
                $address = $this->getNetworkAddress(self::ADDRESS_INT);
            } else if ($offset === 'broadcast') {
                $address = $this->getBroadcastAddress(self::ADDRESS_INT);
            } else {
                // How much the address needs to be adjusted by to account for network address
                $adjustment = (int) ($this->getHostsCount() > 2);
                $address = $this->binaryToLong($this->address) + $offset + $adjustment;
            }

            return $this->longToSubnet($address);
        }
        public function offsetSet ($offset, $value) {}
        public function offsetUnset ($offset) {}

        /*
         * Iterator interface methods
         */
        public function current () {
            return $this->offsetGet($this->iteratorOffset);
        }
        public function key () {
            return $this->iteratorOffset;
        }
        public function next () {
            $this->iteratorOffset++;
        }
        public function rewind () {
            $this->iteratorOffset = 0;
        }
        public function valid () {
            return $this->iteratorOffset < $this->getHostsCount();
        }

        /*
         * Data access methods
         */
        public function getHosts ($mode = self::ADDRESS_SUBNET) {
            // Parse flags and initialise vars
            $bin = (bool) ($mode & self::ADDRESS_BINARY);
            $int = (bool) ($mode & self::ADDRESS_INT);
            $dd = (bool) ($mode & self::ADDRESS_DOTDEC);
            $base = $this->binaryToLong($this->address);
            $mask = $this->binaryToLong($this->mask);
            $hasNwBc = !($mask & 0x03);
            $result = array();

            // Get network address if requested
            if (($mode & self::HOSTS_WITH_NETWORK) && $hasNwBc) {
                $result[] = $base;
            }

            // Get hosts
            for ($current = $hasNwBc ? $base + 1 : $base; ($current & $mask) === $base; $current++) {
                $result[] = $current;
            }

            // Remove broadcast address if present and not requested
            if ($hasNwBc && !($mode & self::HOSTS_WITH_BROADCAST)) {
                array_pop($result);
            }

            // Convert to the correct type
            if ($bin) {
                $result = array_map(array($this, 'longToBinary'), $result);
            } else if ($dd) {
                $result = array_map(array($this, 'longToDottedDecimal'), $result);
            } else if (!$int) {
                $result = array_map(array($this, 'longToSubnet'), $result);
            }

            return $result;
        }
        public function getHostsCount () {
            $count = $this->getBroadcastAddress(self::ADDRESS_INT) - $this->getNetworkAddress(self::ADDRESS_INT);
            return $count > 2 ? $count - 1 : $count + 1; // Adjust return value to exclude network/broadcast addresses
        }
        public function getNetworkAddress ($mode = self::ADDRESS_SUBNET) {
            return $this->binaryToX($this->address, $mode);
        }
        public function getBroadcastAddress ($mode = self::ADDRESS_SUBNET) {
            return $this->binaryToX($this->address | ~$this->mask, $mode);
        }
        public function getMask ($mode = self::ADDRESS_DOTDEC) {
            return $this->binaryToX($this->mask, $mode);
        }

        /*
         * Stringify methods
         */
        public function __toString () {
            if ($this->getHostsCount() === 1) {
                $result = $this->toDottedDecimal();
            } else {
                $result = $this->toCIDR();
            }
            return $result;
        }
        public function toDottedDecimal () {
            $result = $this->getNetworkAddress(self::ADDRESS_DOTDEC);
            if ($this->mask !== "\xFF\xFF\xFF\xFF") {
                $result .= '/'.$this->getMask(self::ADDRESS_DOTDEC);
            }
            return $result;
        }
        public function toCIDR () {
            $address = $this->getNetworkAddress(self::ADDRESS_DOTDEC);
            $cidr = strlen(trim(sprintf('%b', $this->getMask(self::ADDRESS_INT)), '0')); // TODO: Improve this mechanism
            return $address.'/'.$cidr;
        }

        /*
         * Comparison methods
         */
        public function contains ($subject) {
            $this->normaliseComparisonSubject($subject);

            $subjectAddress = $subject->getNetworkAddress(self::ADDRESS_BINARY);
            $subjectMask = $subject->getMask(self::ADDRESS_BINARY);

            return $this->mask !== $subjectMask && ($this->mask | ($this->mask ^ $subjectMask)) !== $this->mask && ($subjectAddress & $this->mask) === $this->address;
        }

        public function within ($subject) {
            $this->normaliseComparisonSubject($subject);

            $subjectAddress = $subject->getNetworkAddress(self::ADDRESS_BINARY);
            $subjectMask = $subject->getMask(self::ADDRESS_BINARY);

            return $this->mask !== $subjectMask && ($this->mask | ($this->mask ^ $subjectMask)) === $this->mask && ($this->address & $subjectMask) === $subjectAddress;
        }
        public function equalTo ($subject) {
            $this->normaliseComparisonSubject($subject);

            return $this->address === $subject->getNetworkAddress(self::ADDRESS_BINARY) && $this->mask === $subject->getMask(self::ADDRESS_BINARY);
        }
        public function intersect ($subject) {
            $this->normaliseComparisonSubject($subject);

            return $this->equalTo($subject) || $this->contains($subject) || $this->within($subject);
        }

    }

这些的示例用法：
// Also accepts dotted decimal mask. The mask may also be passed to the second
// argument. Any valid combination of dotted decimal, CIDR and integers will be
// accepted
$subnet = new IPv4Subnet('192.168.0.0/24');

// These methods will accept a string or another instance
var_dump($subnet->contains('192.168.0.1')); //TRUE
var_dump($subnet->contains('192.168.1.1')); //FALSE
var_dump($subnet->contains('192.168.0.0/16')); //FALSE
var_dump($subnet->within('192.168.0.0/16')); //TRUE
// ...hopefully you get the picture. intersect() returns TRUE if any of the
// other three match.

该类还实现了迭代器
接口，允许您迭代子网中的所有地址。迭代器不包括可以单独检索的网络地址和广播地址
例如：
$subnet = new IPv4Subnet('192.168.0.0/28');
echo "Network: ", $subnet->getNetworkAddress(),
     "; Broadcast: ", $subnet->getBroadcastAddress(),
     "\nHosts:\n";
foreach ($subnet as $host) {
    echo $host, "\n";
}

该类还实现了ArrayAccess
，允许您将其视为一个数组：
$subnet = new IPv4Subnet('192.168.0.0/28');
echo $subnet['network'], "\n"; // 192.168.0.0
echo $subnet[0], "\n"; // 192.168.0.1
// ...
echo $subnet[13], "\n"; // 192.168.0.14
echo $subnet['broadcast'], "\n"; // 192.168.0.15

注意：访问子网主机地址的迭代器/数组方法将返回另一个IPv4Subnet
对象。该类实现了\uuuToString（）
，如果IP地址表示单个地址，它将以虚线小数形式返回，如果它表示多个地址，则返回CIDR。通过调用相关的get*（）
方法并传递所需的标志（参见类顶部定义的常量），可以直接以字符串或整数的形式访问数据
所有操作都是32位和64位安全的。兼容性应符合第5.2节的要求（尽管未进行彻底测试）+


为了完整性，我设想您的用例将按照以下思路实现：
public function addSubnet ($newSubnet) {
    $newSubnet = new IPv4Subnet($newSubnet);
    foreach ($this->subnets as &$existingSubnet) {
        if ($existingSubnet->contains($newSubnet)) {
            throw new Exception('Subnet already added');
        } else if ($existingSubnet->within($newSubnet)) {
            $existingSubnet = $newSubnet;
            return;
        }
    }
    $this->subnets[] = $newSubnet;
}

两件事，您多次执行相同的explode
操作。您可以使用list（$mask1，$net1）
只执行一次。查看str\u pad
，这些填充循环是不必要的。返回最大值的三元比较是不必要的，请使用max
（尽管我确信您实际上想要min
）。除此之外，它本质上做的事情和我的一样。+1用于超越职责的召唤；）喝点咖啡因后，我会尝试理解中包含的所有按位魔法。再次感谢Dave。我还需要对它进行测试，但我很确定我需要的魔法就在这里：）如果没有，我就在聊天中给你设置bug：）不过这只是一件小事，你的类不会覆盖ArrayAccess的offsetUnset方法。不过很容易修好。哦，事实上是的。。为什么我的netbeans会让我烦恼：）@DamienOvereem这个类被设计成是不可变的，因为允许地址/掩码被改变会打开一整罐蠕虫。此外，如果允许在子网的中间更改单个项，这将是毫无意义的，因为它将不再是一个完整的子网。如果您的IDE对空方法有问题，请添加return对他们的陈述很可能会让他们再次感到高兴。谢谢你的回答。戴夫做得很好，但是你的帮助，一直以来，都是非常感谢的+1.
public function addSubnet ($newSubnet) {
    $newSubnet = new IPv4Subnet($newSubnet);
    foreach ($this->subnets as &$existingSubnet) {
        if ($existingSubnet->contains($newSubnet)) {
            throw new Exception('Subnet already added');
        } else if ($existingSubnet->within($newSubnet)) {
            $existingSubnet = $newSubnet;
            return;
        }
    }
    $this->subnets[] = $newSubnet;
}