using System;using System.Runtime.InteropServices;using System.ComponentModel;namespace PoshHttp
{ public class Proxies
{ public static bool UnsetProxy()
{ return SetProxy(null, null);
} public static bool SetProxy(string strProxy)
{ return SetProxy(strProxy, null);
} public static bool SetProxy(string strProxy, string exceptions)
{
InternetPerConnOptionList list = new InternetPerConnOptionList(); int optionCount = string.IsNullOrEmpty(strProxy) ? 1 : (string.IsNullOrEmpty(exceptions) ? 2 : 3);
InternetConnectionOption[] options = new InternetConnectionOption[optionCount]; // USE a proxy server ...
options[0].m_Option = PerConnOption.INTERNET_PER_CONN_FLAGS;
options[0].m_Value.m_Int = (int)((optionCount < 2) ? PerConnFlags.PROXY_TYPE_DIRECT : (PerConnFlags.PROXY_TYPE_DIRECT | PerConnFlags.PROXY_TYPE_PROXY)); // use THIS proxy server
if (optionCount > 1)
{
options[1].m_Option = PerConnOption.INTERNET_PER_CONN_PROXY_SERVER;
options[1].m_Value.m_StringPtr = Marshal.StringToHGlobalAuto(strProxy); // except for these addresses ...
if (optionCount > 2)
{
options[2].m_Option = PerConnOption.INTERNET_PER_CONN_PROXY_BYPASS;
options[2].m_Value.m_StringPtr = Marshal.StringToHGlobalAuto(exceptions);
}
} // default stuff
list.dwSize = Marshal.SizeOf(list);
list.szConnection = IntPtr.Zero;
list.dwOptionCount = options.Length;
list.dwOptionError = 0; int optSize = Marshal.SizeOf(typeof(InternetConnectionOption)); // make a pointer out of all that ...
IntPtr optionsPtr = Marshal.AllocCoTaskMem(optSize * options.Length); // copy the array over into that spot in memory ...
for (int i = 0; i < options.Length; ++i)
{
IntPtr opt = new IntPtr(optionsPtr.ToInt32() + (i * optSize));
Marshal.StructureToPtr(options[i], opt, false);
}
list.options = optionsPtr; // and then make a pointer out of the whole list
IntPtr ipcoListPtr = Marshal.AllocCoTaskMem((Int32)list.dwSize);
Marshal.StructureToPtr(list, ipcoListPtr, false); // and finally, call the API method!
int returnvalue = NativeMethods.InternetSetOption(IntPtr.Zero,
InternetOption.INTERNET_OPTION_PER_CONNECTION_OPTION,
ipcoListPtr, list.dwSize) ? -1 : 0; if (returnvalue == 0)
{ // get the error codes, they might be helpful
returnvalue = Marshal.GetLastWin32Error();
} // FREE the data ASAP Marshal.FreeCoTaskMem(optionsPtr);
Marshal.FreeCoTaskMem(ipcoListPtr); if (returnvalue > 0)
{ // throw the error codes, they might be helpful
throw new Win32Exception(Marshal.GetLastWin32Error());
} return (returnvalue < 0);
}
} #region WinInet structures
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)] public struct InternetPerConnOptionList
{ public int dwSize; // size of the INTERNET_PER_CONN_OPTION_LIST struct
public IntPtr szConnection; // connection name to set/query options
public int dwOptionCount; // number of options to set/query
public int dwOptionError; // on error, which option failed //[MarshalAs(UnmanagedType.)]
public IntPtr options;
};
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)] public struct InternetConnectionOption
{ static readonly int Size; public PerConnOption m_Option; public InternetConnectionOptionValue m_Value; static InternetConnectionOption()
{
InternetConnectionOption.Size = Marshal.SizeOf(typeof(InternetConnectionOption));
} // Nested Types [StructLayout(LayoutKind.Explicit)] public struct InternetConnectionOptionValue
{ // Fields
[FieldOffset(0)] public System.Runtime.InteropServices.ComTypes.FILETIME m_FileTime;
[FieldOffset(0)] public int m_Int;
[FieldOffset(0)] public IntPtr m_StringPtr;
}
} #endregion
#region WinInet enums //
// options manifests for Internet{Query|Set}Option // public enum InternetOption : uint
{
INTERNET_OPTION_PER_CONNECTION_OPTION = 75
} //
// Options used in INTERNET_PER_CONN_OPTON struct // public enum PerConnOption
{
INTERNET_PER_CONN_FLAGS = 1, // Sets or retrieves the connection type. The Value member will contain one or more of the values from PerConnFlags
INTERNET_PER_CONN_PROXY_SERVER = 2, // Sets or retrieves a string containing the proxy servers.
INTERNET_PER_CONN_PROXY_BYPASS = 3, // Sets or retrieves a string containing the URLs that do not use the proxy server.
INTERNET_PER_CONN_AUTOCONFIG_URL = 4//, // Sets or retrieves a string containing the URL to the automatic configuration script.
} //
// PER_CONN_FLAGS // [Flags] public enum PerConnFlags
{
PROXY_TYPE_DIRECT = 0x00000001, // direct to net
PROXY_TYPE_PROXY = 0x00000002, // via named proxy
PROXY_TYPE_AUTO_PROXY_URL = 0x00000004, // autoproxy URL
PROXY_TYPE_AUTO_DETECT = 0x00000008 // use autoproxy detection } #endregion
internal static class NativeMethods
{
[DllImport("WinInet.dll", SetLastError = true, CharSet = CharSet.Auto)]
[return: MarshalAs(UnmanagedType.Bool)] public static extern bool InternetSetOption(IntPtr hInternet, InternetOption dwOption, IntPtr lpBuffer, int dwBufferLength);
}
}
