php – 测试cidr表示法中的网络是否与另一个网络重叠_php教程

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php – 测试cidr表示法中的网络是否与另一个网络重叠

发布时间：2022-04-30 发布网站：脚本宝典

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我正在寻找一种有效测试一个cidr标记网络是否与另一个重叠的PHP算法.

基本上我有以下情况：

一系列cidr地址：

$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重叠时,此方法应该抛出异常.

所以即.如果添加了192.168.10.0/25,则应抛出异常.

有没有人/知道/“可以想到”一种方法来有效地测试这个？

这是之前在聊天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东西.

<?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 &amp; 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) === '')) {
                $address = array(0,0);
            } else if (is_int($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],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);
            $address += array(0,0);
            if ($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);
            } else if (is_int($mask)) {
                $mask = $this->longToByteArray($mask);
            } else if (is_string($mask)) {
                $mask = preg_split('#\s*\.\s*#',trim($mask),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
                            $mask = array(0,0);
                        } else if ($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);
        }

    }

为了做你想做的事,这个班提供了4种方法：

contains()
within()
equalTo()
intersect()

这些示例用法：

// 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Iterator接口,允许您遍历子网中的所有地址.迭代器排除网络和广播地址,可以单独检索.

例：

$subnet = new IPv4subnet('192.168.0.0/28');
echo "Network: ",$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__toString(),如果它表示单个地址,则将IP地址作为点分十进制返回,如果它代表多个地址,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形式访问数据.

所有操作都是32位和64位安全的.兼容性应该(尽管没有经过彻底测试)5.2

See it working

为了完整起见,我想你的用例将按以下方式实现：

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;
}