using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.IO;
using System.Diagnostics;
public class RedirectMode
{
public static readonly int Mode_1 = 1;
public static readonly int Mode_2 = 2;
}
public class IPFormat
{
public static readonly int HeaderLength = 8;
public static readonly int IndexRecLength = 7;
public static readonly int IndexOffset = 3;
public static readonly int RecOffsetLength = 3;
public static readonly string UnknownCountry = "未知的国家";
public static readonly string UnknownZone = "未知的地区";
public static uint ToUint(byte[] val)
{
if (val.Length > 4) throw new ArgumentException();
if (val.Length < 4)
{
byte[] copyBytes = new byte[4];
Array.Copy(val, 0, copyBytes, 0, val.Length);
return BitConverter.ToUInt32(copyBytes, 0);
}
else
{
return BitConverter.ToUInt32(val, 0);
}
}
}
public class IPLocation
{
private IPAddress m_ip;
private string m_country;
private string m_loc;
public IPLocation(IPAddress ip, string country, string loc)
{
m_ip = ip;
m_country = country;
m_loc = loc;
}
public IPAddress IP
{
get { return m_ip; }
}
public string Country
{
get { return m_country; }
}
public string Zone
{
get { return m_loc; }
}
}
/// <summary>
/// This class used to control ip seek
/// </summary>
public class IPSeeker
{
private string m_libPath;
private uint m_indexStart;
private uint m_indexEnd;
public IPSeeker(string libPath)
{
m_libPath = libPath;
//Locate the index block
using (FileStream fs = new FileStream(m_libPath, FileMode.Open, FileAccess.Read))
{
BinaryReader reader = new BinaryReader(fs);
Byte[] header = reader.ReadBytes(IPFormat.HeaderLength);
m_indexStart = BitConverter.ToUInt32(header, 0);
m_indexEnd = BitConverter.ToUInt32(header, 4);
}
}
/// <summary>
/// 输入IP地址，获取IP所在的地区信息
/// </summary>
/// <param name="ip">待查询的IP地址</param>
/// <returns></returns>
public IPLocation GetLocation(IPAddress ip)
{
using (FileStream fs = new FileStream(m_libPath, FileMode.Open, FileAccess.Read))
{
BinaryReader reader = new BinaryReader(fs);
//Because it is network order(BigEndian), so we need to transform it into LittleEndian
Byte[] givenIpBytes = BitConverter.GetBytes(IPAddress.NetworkToHostOrder(BitConverter.ToInt32(ip.GetAddressBytes(), 0)));
uint offset = FindStartPos(fs, reader, m_indexStart, m_indexEnd, givenIpBytes);
return GetIPInfo(fs, reader, offset, ip, givenIpBytes);
}
}
#region private method
private uint FindStartPos(FileStream fs, BinaryReader reader, uint m_indexStart, uint m_indexEnd, byte[] givenIp)
{
uint givenVal = BitConverter.ToUInt32(givenIp, 0);
fs.Position = m_indexStart;
while (fs.Position <= m_indexEnd)
{
Byte[] bytes = reader.ReadBytes(IPFormat.IndexRecLength);
uint curVal = BitConverter.ToUInt32(bytes, 0);
if (curVal > givenVal)
{
fs.Position = fs.Position - 2 * IPFormat.IndexRecLength;
bytes = reader.ReadBytes(IPFormat.IndexRecLength);
byte[] offsetByte = new byte[4];
Array.Copy(bytes, 4, offsetByte, 0, 3);
return BitConverter.ToUInt32(offsetByte, 0);
}
}
return 0;
}
private IPLocation GetIPInfo(FileStream fs, BinaryReader reader, long offset, IPAddress ipToLoc, Byte[] ipBytes)
{
fs.Position = offset;
//To confirm that the given ip is within the range of record IP range
byte[] endIP = reader.ReadBytes(4);
uint endIpVal = BitConverter.ToUInt32(endIP, 0);
uint ipVal = BitConverter.ToUInt32(ipBytes, 0);
if (endIpVal < ipVal) return null;
string country;
string zone;
//Read the Redirection pattern byte
Byte pattern = reader.ReadByte();
if (pattern == RedirectMode.Mode_1)
{
Byte[] countryOffsetBytes = reader.ReadBytes(IPFormat.RecOffsetLength);
uint countryOffset = IPFormat.ToUint(countryOffsetBytes);
if (countryOffset == 0) return GetUnknownLocation(ipToLoc);
fs.Position = countryOffset;
if (fs.ReadByte() == RedirectMode.Mode_2)
{
return ReadMode2Record(fs, reader, ipToLoc);
}
else
{
fs.Position--;
country = ReadString(reader);
zone = ReadZone(fs, reader, Convert.ToUInt32(fs.Position));
}
}
else if (pattern == RedirectMode.Mode_2)
{
return ReadMode2Record(fs, reader, ipToLoc);
}
else
{
fs.Position--;
country = ReadString(reader);
zone = ReadZone(fs, reader, Convert.ToUInt32(fs.Position));
}
return new IPLocation(ipToLoc, country, zone);
}
//When it is in Mode 2
private IPLocation ReadMode2Record(FileStream fs, BinaryReader reader, IPAddress ip)
{
uint countryOffset = IPFormat.ToUint(reader.ReadBytes(IPFormat.RecOffsetLength));
uint curOffset = Convert.ToUInt32(fs.Position);
if (countryOffset == 0) return GetUnknownLocation(ip);
fs.Position = countryOffset;
string country = ReadString(reader);
string zone = ReadZone(fs, reader, curOffset);
return new IPLocation(ip, country, zone);
}
//return a Unknown Location
private IPLocation GetUnknownLocation(IPAddress ip)
{
string country = IPFormat.UnknownCountry;
string zone = IPFormat.UnknownZone;
return new IPLocation(ip, country, zone);
}
//Retrieve the zone info
private string ReadZone(FileStream fs, BinaryReader reader, uint offset)
{
fs.Position = offset;
byte b = reader.ReadByte();
if (b == RedirectMode.Mode_1 || b == RedirectMode.Mode_2)
{
uint zoneOffset = IPFormat.ToUint(reader.ReadBytes(3));
if (zoneOffset == 0) return IPFormat.UnknownZone;
return ReadZone(fs, reader, zoneOffset);
}
else
{
fs.Position--;
return ReadString(reader);
}
}
private string ReadString(BinaryReader reader)
{
List<byte> stringLst = new List<byte>();
byte byteRead = 0;
while ((byteRead = reader.ReadByte()) != 0)
{
stringLst.Add(byteRead);
}
return Encoding.GetEncoding("gb2312").GetString(stringLst.ToArray());
}
#endregion
}
第二步：编写测试文件，Default.aspx.cs中粘贴覆盖以下代码，其中鹅黄色为测试代码；然后F5测试，弹窗说明成功；
