/// <summary>
/// 读取host表
/// </summary>
/// <param name="dnsPack"></param>
/// <param name="cache"></param>
/// <returns></returns>
public bool ReadHost(DNSProxy.DnsPack dnsPack, out byte[] cache)
{
try {
if (!isInit)
{
throw new Exception();
}
OleDbCommand cmd;
cmd = conn.CreateCommand();
cmd.CommandText = "select QueryDns from dnsHost where QueryName = ? and QueryType = ?";
cmd.Parameters.Add("@QueryName", OleDbType.VarChar).Value = dnsPack.QueryRecords[0].QueryName;
cmd.Parameters.Add("@QueryType", OleDbType.VarChar).Value = dnsPack.QueryRecords[0].QueryType;
string Value = (string)cmd.ExecuteScalar();
if (Value != null && Value != string.Empty)
{
switch (dnsPack.QueryRecords[0].QueryType)
{
case DNSProxy.QueryType.A:
IPAddress iP;
if (!IPAddress.TryParse(Value, out iP))
{
break;
}
string[] ips = iP.ToString().Split('.');
byte[] ipBtye = new byte[] { byte.Parse(ips[0]), byte.Parse(ips[1]), byte.Parse(ips[2]), byte.Parse(ips[3]) };
dnsPack.ResouceRecords.Add(new DNSProxy.ResouceRecord {
QueryClass = 1,
QueryType = DNSProxy.QueryType.A,
QueryName = dnsPack.QueryRecords[0].QueryName,
Datas = ipBtye,
TTL = 0
});
break;
default:
break;
}
cache = dnsPack.ToBytes();
return(cache != null);
}
throw new Exception();
} catch (Exception) {
cache = new byte[0];
return(false);
}
}
/// <summary>
/// 写入缓存到数据库
/// </summary>
/// <param name="dataTable"></param>
/// <returns></returns>
public bool WriteCache(DNSProxy.DnsPack dnsPack)
{
try {
if (!isInit)
{
throw new Exception();
}
bool result;
OleDbCommand cmd = null;
OleDbTransaction transaction = null;
try {
#region 保存总账单
// 开始事务
transaction = conn.BeginTransaction();
cmd = conn.CreateCommand();
cmd.Transaction = transaction;
cmd.Connection = conn;
cmd.CommandText = "insert into dnscache(QueryName, QueryType, QueryClass, QueryDns) values(?, ?, ?, ?)";
cmd.Parameters.Add("@QueryName", OleDbType.VarChar).Value = dnsPack.QueryRecords[0].QueryName;
cmd.Parameters.Add("@QueryType", OleDbType.VarChar).Value = dnsPack.QueryRecords[0].QueryType;
cmd.Parameters.Add("@QueryClass", OleDbType.VarChar).Value = dnsPack.QueryRecords[0].QueryClass;
cmd.Parameters.Add("@ImageBinary", OleDbType.Binary, dnsPack.ToBytes().Length).Value = dnsPack.ToBytes();
if (cmd.ExecuteNonQuery() < 0)
{
throw new Exception();
}
#endregion
//提交事务
transaction.Commit();
result = true;
} catch {
//异常时回滚事务
result = false;
transaction.Rollback();
} finally {
cmd.Dispose();
transaction.Dispose();
}
return(result);
} catch {
return(false);
}
}
/// <summary>
/// 获取缓存数据
/// </summary>
/// <returns></returns>
public bool ReadCache(DNSProxy.DnsPack dnsPack, out byte[] cache)
{
try {
if (!isInit)
{
throw new Exception();
}
OleDbCommand cmd;
cmd = conn.CreateCommand();
cmd.CommandText = "select QueryDns from dnscache where QueryName = ? and QueryType = ?";
cmd.Parameters.Add("@QueryName", OleDbType.VarChar).Value = dnsPack.QueryRecords[0].QueryName;
cmd.Parameters.Add("@QueryType", OleDbType.VarChar).Value = dnsPack.QueryRecords[0].QueryType;
byte[] bytes = (byte[])cmd.ExecuteScalar();
cache = bytes;
return(cache != null);
} catch {
cache = new byte[0];
return(false);
}
}
