Using a managed library from native code

  • Thread starter Thread starter dadi.armannss
  • Start date Start date
D

dadi.armannss

Hi

I have been experimenting with writing managed libraries (C#/.NET 2.0)
for use in native applications with good results. This has been
achieved by disassembling the managed library, adding IL code to
export the required functions, and then using ILAsm to re-assemble
the .NET assembly. The IL code changes required are the following:

..corflags 0x00000001 -> .corflags 0x00000002

Added:
..vtfixup [1] int32 fromunmanaged at VT_01
..data VT_01 = int32(0)

Added within exported function scope:
..vtentry 1 : 1
..export [1] as Test

After applying these changes, one can use the managed library as if it
was native, either from a native app, using LoadLibrary/
GetProcAddress, or from a managed app using DllImport.

Now when I do the same for a compact framework assembly and try to
load and execute a function from that managed library on Windows CE
5.0, I get an access violation.

I have confirmed that the code that loads the library is successful in
locating the exported lib function, so the access violation is either
in the lib function or somewhere in the glue between the native app
and the managed lib. The code for each follows:

[Native application]
typedef void (*PFN_Test)(void);
void main() {
HINSTANCE hManagedLib = LoadLibrary(_T("CFManagedDLL.dll"));
if( hManagedLib ) {
PFN_Test exportedFunc =
(PFN_Test)GetProcAddress(hManagedLib, L"Test");
if( exportedFunc != NULL)
exportedFunc();
}
return 0;
}

[Managed library]
using System;
using System.Collections.Generic;
using System.Text;

namespace CFManagedDLL {
public class Class1 {
public static void Test() {
System.Console.Out.WriteLine("Compact Framework Managed
DLL");
}
}
}

[Altered IL Code for Managed library]
..assembly extern mscorlib
{
.publickeytoken = (96 9D B8 05 3D 33 22
AC ) // ....=3".
.ver 2:0:0:0
}
..assembly CFManagedDLL
{
.custom instance void
[mscorlib]System.Runtime.InteropServices.GuidAttribute::.ctor(string)
= ( 01 00 24 31 36 34 31 61 66 34 38 2D 65 37 63 62 // ..$1641af48-
e7cb

2D 34 61 64 31 2D 38 36 63 32 2D 66 62 37 32 36 // -4ad1-86c2-fb726

34 39 34 62 66 65 30 00 00 ) // 494bfe0..
.custom instance void
[mscorlib]System.Runtime.InteropServices.ComVisibleAttribute::.ctor(bool)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyTrademarkAttribute::.ctor(string)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyCopyrightAttribute::.ctor(string)
= ( 01 00 12 43 6F 70 79 72 69 67 68 74 20 C2 A9
20 // ...Copyright ..

20 32 30 30 37 00 00 ) // 2007..
.custom instance void
[mscorlib]System.Reflection.AssemblyProductAttribute::.ctor(string) =
( 01 00 0C 43 46 4D 61 6E 61 67 65 64 44 4C 4C
00 // ...CFManagedDLL.

00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyCompanyAttribute::.ctor(string) =
( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyConfigurationAttribute::.ctor(string)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyDescriptionAttribute::.ctor(string)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyTitleAttribute::.ctor(string) =
( 01 00 0C 43 46 4D 61 6E 61 67 65 64 44 4C 4C
00 // ...CFManagedDLL.

00 )

// --- The following custom attribute is added automatically, do not
uncomment -------
// .custom instance void
[mscorlib]System.Diagnostics.DebuggableAttribute::.ctor(valuetype
[mscorlib]System.Diagnostics.DebuggableAttribute/DebuggingModes) =
( 01 00 07 01 00 00 00 00 )

.hash algorithm 0x00008004
.ver 1:0:2602:17354
}
..module CFManagedDLL.dll
// MVID: {C072D8C7-8D33-477C-BB9C-275822BD1E76}
..imagebase 0x00400000
..file alignment 0x00001000
..stackreserve 0x00100000
..subsystem 0x0009 // WINDOWS_CUI
..corflags 0x00000002
..vtfixup [1] int32 fromunmanaged at VT_01
..data VT_01 = int32(0)
// Image base: 0x005F0000


// =============== CLASS MEMBERS DECLARATION ===================

..class public auto ansi beforefieldinit CFManagedDLL.Class1
extends [mscorlib]System.Object
{
.method public hidebysig static void Test() cil managed
{
.vtentry 1 : 1
.export [1] as Test
// Code size 18 (0x12)
.maxstack 8
IL_0000: nop
IL_0001: call class [mscorlib]System.IO.TextWriter
[mscorlib]System.Console::get_Out()
IL_0006: ldstr "Compact Framework Managed DLL"
IL_000b: callvirt instance void
[mscorlib]System.IO.TextWriter::WriteLine(string)
IL_0010: nop
IL_0011: ret
} // end of method Class1::Test

.method public hidebysig specialname rtspecialname
instance void .ctor() cil managed
{
// Code size 7 (0x7)
.maxstack 8
IL_0000: ldarg.0
IL_0001: call instance void
[mscorlib]System.Object::.ctor()
IL_0006: ret
} // end of method Class1::.ctor

} // end of class CFManagedDLL.Class1
 
This is not supported at all. If you need to use managed code from native
code you'll need to run your managed app and use an IPC method to exchange
data with it. See Daniels posts on IPC methods:-
http://www.danielmoth.com/Blog/2004/09/ipc-with-cf-on-ce-part-1.html

Peter

--
Peter Foot
Device Application Development MVP
www.peterfoot.net | www.inthehand.com


Hi

I have been experimenting with writing managed libraries (C#/.NET 2.0)
for use in native applications with good results. This has been
achieved by disassembling the managed library, adding IL code to
export the required functions, and then using ILAsm to re-assemble
the .NET assembly. The IL code changes required are the following:

.corflags 0x00000001 -> .corflags 0x00000002

Added:
.vtfixup [1] int32 fromunmanaged at VT_01
.data VT_01 = int32(0)

Added within exported function scope:
.vtentry 1 : 1
.export [1] as Test

After applying these changes, one can use the managed library as if it
was native, either from a native app, using LoadLibrary/
GetProcAddress, or from a managed app using DllImport.

Now when I do the same for a compact framework assembly and try to
load and execute a function from that managed library on Windows CE
5.0, I get an access violation.

I have confirmed that the code that loads the library is successful in
locating the exported lib function, so the access violation is either
in the lib function or somewhere in the glue between the native app
and the managed lib. The code for each follows:

[Native application]
typedef void (*PFN_Test)(void);
void main() {
HINSTANCE hManagedLib = LoadLibrary(_T("CFManagedDLL.dll"));
if( hManagedLib ) {
PFN_Test exportedFunc =
(PFN_Test)GetProcAddress(hManagedLib, L"Test");
if( exportedFunc != NULL)
exportedFunc();
}
return 0;
}

[Managed library]
using System;
using System.Collections.Generic;
using System.Text;

namespace CFManagedDLL {
public class Class1 {
public static void Test() {
System.Console.Out.WriteLine("Compact Framework Managed
DLL");
}
}
}

[Altered IL Code for Managed library]
.assembly extern mscorlib
{
.publickeytoken = (96 9D B8 05 3D 33 22
AC ) // ....=3".
.ver 2:0:0:0
}
.assembly CFManagedDLL
{
.custom instance void
[mscorlib]System.Runtime.InteropServices.GuidAttribute::.ctor(string)
= ( 01 00 24 31 36 34 31 61 66 34 38 2D 65 37 63 62 // ..$1641af48-
e7cb

2D 34 61 64 31 2D 38 36 63 32 2D 66 62 37 32 36 // -4ad1-86c2-fb726

34 39 34 62 66 65 30 00 00 ) // 494bfe0..
.custom instance void
[mscorlib]System.Runtime.InteropServices.ComVisibleAttribute::.ctor(bool)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyTrademarkAttribute::.ctor(string)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyCopyrightAttribute::.ctor(string)
= ( 01 00 12 43 6F 70 79 72 69 67 68 74 20 C2 A9
20 // ...Copyright ..

20 32 30 30 37 00 00 ) // 2007..
.custom instance void
[mscorlib]System.Reflection.AssemblyProductAttribute::.ctor(string) =
( 01 00 0C 43 46 4D 61 6E 61 67 65 64 44 4C 4C
00 // ...CFManagedDLL.

00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyCompanyAttribute::.ctor(string) =
( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyConfigurationAttribute::.ctor(string)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyDescriptionAttribute::.ctor(string)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyTitleAttribute::.ctor(string) =
( 01 00 0C 43 46 4D 61 6E 61 67 65 64 44 4C 4C
00 // ...CFManagedDLL.

00 )

// --- The following custom attribute is added automatically, do not
uncomment -------
// .custom instance void
[mscorlib]System.Diagnostics.DebuggableAttribute::.ctor(valuetype
[mscorlib]System.Diagnostics.DebuggableAttribute/DebuggingModes) =
( 01 00 07 01 00 00 00 00 )

.hash algorithm 0x00008004
.ver 1:0:2602:17354
}
.module CFManagedDLL.dll
// MVID: {C072D8C7-8D33-477C-BB9C-275822BD1E76}
.imagebase 0x00400000
.file alignment 0x00001000
.stackreserve 0x00100000
.subsystem 0x0009 // WINDOWS_CUI
.corflags 0x00000002
.vtfixup [1] int32 fromunmanaged at VT_01
.data VT_01 = int32(0)
// Image base: 0x005F0000


// =============== CLASS MEMBERS DECLARATION ===================

.class public auto ansi beforefieldinit CFManagedDLL.Class1
extends [mscorlib]System.Object
{
.method public hidebysig static void Test() cil managed
{
.vtentry 1 : 1
.export [1] as Test
// Code size 18 (0x12)
.maxstack 8
IL_0000: nop
IL_0001: call class [mscorlib]System.IO.TextWriter
[mscorlib]System.Console::get_Out()
IL_0006: ldstr "Compact Framework Managed DLL"
IL_000b: callvirt instance void
[mscorlib]System.IO.TextWriter::WriteLine(string)
IL_0010: nop
IL_0011: ret
} // end of method Class1::Test

.method public hidebysig specialname rtspecialname
instance void .ctor() cil managed
{
// Code size 7 (0x7)
.maxstack 8
IL_0000: ldarg.0
IL_0001: call instance void
[mscorlib]System.Object::.ctor()
IL_0006: ret
} // end of method Class1::.ctor

} // end of class CFManagedDLL.Class1
Click to expand...
 
I know it is not officially supported, but you can do it in the
fullblown framework by manually creating a V-table and changing the
header of the PE file (as shown in the accompanying IL code). Can you
elaborate on which specific part is not possible on WinCE/.NET CF?

This is not supported at all. If you need to use managed code from native
code you'll need to run your managed app and use an IPC method to exchange
data with it. See Daniels posts on IPC methods:-http://www.danielmoth.com/Blog/2004/09/ipc-with-cf-on-ce-part-1.html

Peter

--
Peter Foot
Device Application Development MVPwww.peterfoot.net|www.inthehand.com


Hi
Click to expand...
I have been experimenting with writing managed libraries (C#/.NET 2.0)
for use in native applications with good results. This has been
achieved by disassembling the managed library, adding IL code to
export the required functions, and then using ILAsm to re-assemble
the .NET assembly. The IL code changes required are the following:
Click to expand...
.corflags 0x00000001 -> .corflags 0x00000002
Click to expand...
Added:
.vtfixup [1] int32 fromunmanaged at VT_01
.data VT_01 = int32(0)
Click to expand...
Added within exported function scope:
.vtentry 1 : 1
.export [1] as Test
Click to expand...
After applying these changes, one can use the managed library as if it
was native, either from a native app, using LoadLibrary/
GetProcAddress, or from a managed app using DllImport.
Click to expand...
Now when I do the same for a compact framework assembly and try to
load and execute a function from that managed library on Windows CE
5.0, I get an access violation.
Click to expand...
I have confirmed that the code that loads the library is successful in
locating the exported lib function, so the access violation is either
in the lib function or somewhere in the glue between the native app
and the managed lib. The code for each follows:
Click to expand...
[Native application]
typedef void (*PFN_Test)(void);
void main() {
HINSTANCE hManagedLib = LoadLibrary(_T("CFManagedDLL.dll"));
if( hManagedLib ) {
PFN_Test exportedFunc =
(PFN_Test)GetProcAddress(hManagedLib, L"Test");
if( exportedFunc != NULL)
exportedFunc();
}
return 0;
}
Click to expand...
[Managed library]
using System;
using System.Collections.Generic;
using System.Text;
Click to expand...
namespace CFManagedDLL {
public class Class1 {
public static void Test() {
System.Console.Out.WriteLine("Compact Framework Managed
DLL");
}
}
}
Click to expand...
[Altered IL Code for Managed library]
.assembly extern mscorlib
{
.publickeytoken = (96 9D B8 05 3D 33 22
AC ) // ....=3".
.ver 2:0:0:0
}
.assembly CFManagedDLL
{
.custom instance void
[mscorlib]System.Runtime.InteropServices.GuidAttribute::.ctor(string)
= ( 01 00 24 31 36 34 31 61 66 34 38 2D 65 37 63 62 // ..$1641af48-
e7cb
Click to expand...
2D 34 61 64 31 2D 38 36 63 32 2D 66 62 37 32 36 // -4ad1-86c2-fb726
Click to expand...
34 39 34 62 66 65 30 00 00 ) // 494bfe0..
.custom instance void
[mscorlib]System.Runtime.InteropServices.ComVisibleAttribute::.ctor(bool)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyTrademarkAttribute::.ctor(string)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyCopyrightAttribute::.ctor(string)
= ( 01 00 12 43 6F 70 79 72 69 67 68 74 20 C2 A9
20 // ...Copyright ..
Click to expand...
20 32 30 30 37 00 00 ) // 2007..
.custom instance void
[mscorlib]System.Reflection.AssemblyProductAttribute::.ctor(string) =
( 01 00 0C 43 46 4D 61 6E 61 67 65 64 44 4C 4C
00 // ...CFManagedDLL.
Click to expand...
00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyCompanyAttribute::.ctor(string) =
( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyConfigurationAttribute::.ctor(string)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyDescriptionAttribute::.ctor(string)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyTitleAttribute::.ctor(string) =
( 01 00 0C 43 46 4D 61 6E 61 67 65 64 44 4C 4C
00 // ...CFManagedDLL.
Click to expand...
00 )
Click to expand...
// --- The following custom attribute is added automatically, do not
uncomment -------
// .custom instance void
[mscorlib]System.Diagnostics.DebuggableAttribute::.ctor(valuetype
[mscorlib]System.Diagnostics.DebuggableAttribute/DebuggingModes) =
( 01 00 07 01 00 00 00 00 )
Click to expand...
.hash algorithm 0x00008004
.ver 1:0:2602:17354
}
.module CFManagedDLL.dll
// MVID: {C072D8C7-8D33-477C-BB9C-275822BD1E76}
.imagebase 0x00400000
.file alignment 0x00001000
.stackreserve 0x00100000
.subsystem 0x0009 // WINDOWS_CUI
.corflags 0x00000002
.vtfixup [1] int32 fromunmanaged at VT_01
.data VT_01 = int32(0)
// Image base: 0x005F0000
Click to expand...
// =============== CLASS MEMBERS DECLARATION ===================
Click to expand...
.class public auto ansi beforefieldinit CFManagedDLL.Class1
extends [mscorlib]System.Object
{
.method public hidebysig static void Test() cil managed
{
.vtentry 1 : 1
.export [1] as Test
// Code size 18 (0x12)
.maxstack 8
IL_0000: nop
IL_0001: call class [mscorlib]System.IO.TextWriter
[mscorlib]System.Console::get_Out()
IL_0006: ldstr "Compact Framework Managed DLL"
IL_000b: callvirt instance void
[mscorlib]System.IO.TextWriter::WriteLine(string)
IL_0010: nop
IL_0011: ret
} // end of method Class1::Test
Click to expand...
.method public hidebysig specialname rtspecialname
instance void .ctor() cil managed
{
// Code size 7 (0x7)
.maxstack 8
IL_0000: ldarg.0
IL_0001: call instance void
[mscorlib]System.Object::.ctor()
IL_0006: ret
} // end of method Class1::.ctor
Click to expand...
} // end of class CFManagedDLL.Class1
Click to expand...
Click to expand...
 
Hello (e-mail address removed),

I'd venture a guess that the full framework contains a host component, and
..NET PEs contain a stub that when run under Win32 (i.e. with the full framework
around) trigger that host when they attach to the parent process (DLL_PROCESS_ATTACH/DLL_PROCESS_DETACH).
If this is the case, I'd imagine the CF team chose (wisely) not to include
the feature, since it seems (at least to me) problematic at best and useless
at worst.

Regards,
Tomer Gabel (http://www.tomergabel.com)
Monfort Software Engineering Ltd. (http://www.monfort.co.il)

I know it is not officially supported, but you can do it in the
fullblown framework by manually creating a V-table and changing the
header of the PE file (as shown in the accompanying IL code). Can you
elaborate on which specific part is not possible on WinCE/.NET CF?

This is not supported at all. If you need to use managed code from
native

code you'll need to run your managed app and use an IPC method to
exchange

data with it. See Daniels posts on IPC
methods:-http://www.danielmoth.com/Blog/2004/09/ipc-with-cf-on-ce-par
t-1.html

Peter

--
Peter Foot
Device Application Development MVPwww.peterfoot.net|www.inthehand.com

Hi

I have been experimenting with writing managed libraries (C#/.NET
2.0)
for use in native applications with good results. This has been
achieved by disassembling the managed library, adding IL code to
export the required functions, and then using ILAsm to re-assemble
the .NET assembly. The IL code changes required are the following:
.corflags 0x00000001 -> .corflags 0x00000002

Added:
.vtfixup [1] int32 fromunmanaged at VT_01
.data VT_01 = int32(0)
Added within exported function scope:
.vtentry 1 : 1
.export [1] as Test
After applying these changes, one can use the managed library as if
it was native, either from a native app, using LoadLibrary/
GetProcAddress, or from a managed app using DllImport.

Now when I do the same for a compact framework assembly and try to
load and execute a function from that managed library on Windows CE
5.0, I get an access violation.

I have confirmed that the code that loads the library is successful
in locating the exported lib function, so the access violation is
either in the lib function or somewhere in the glue between the
native app and the managed lib. The code for each follows:

[Native application]
typedef void (*PFN_Test)(void);
void main() {
HINSTANCE hManagedLib = LoadLibrary(_T("CFManagedDLL.dll"));
if( hManagedLib ) {
PFN_Test exportedFunc =
(PFN_Test)GetProcAddress(hManagedLib, L"Test");
if( exportedFunc != NULL)
exportedFunc();
}
return 0;
}
[Managed library]
using System;
using System.Collections.Generic;
using System.Text;
namespace CFManagedDLL {
public class Class1 {
public static void Test() {
System.Console.Out.WriteLine("Compact Framework Managed
DLL");
}
}
}
[Altered IL Code for Managed library]
.assembly extern mscorlib
{
.publickeytoken = (96 9D B8 05 3D 33 22
AC ) // ....=3".
.ver 2:0:0:0
}
.assembly CFManagedDLL
{
.custom instance void
[mscorlib]System.Runtime.InteropServices.GuidAttribute::.ctor(string
)
= ( 01 00 24 31 36 34 31 61 66 34 38 2D 65 37 63 62 //
..$1641af48-
e7cb
2D 34 61 64 31 2D 38 36 63 32 2D 66 62 37 32 36 //
-4ad1-86c2-fb726

34 39 34 62 66 65 30 00 00 ) // 494bfe0..
.custom instance void
[mscorlib]System.Runtime.InteropServices.ComVisibleAttribute::.ctor(
bool)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyTrademarkAttribute::.ctor(string
)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyCopyrightAttribute::.ctor(string
)
= ( 01 00 12 43 6F 70 79 72 69 67 68 74 20 C2 A9
20 // ...Copyright ..
20 32 30 30 37 00 00 ) // 2007..
.custom instance void
[mscorlib]System.Reflection.AssemblyProductAttribute::.ctor(string)
=
( 01 00 0C 43 46 4D 61 6E 61 67 65 64 44 4C 4C
00 // ...CFManagedDLL.
00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyCompanyAttribute::.ctor(string)
=
( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyConfigurationAttribute::.ctor(st
ring)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyDescriptionAttribute::.ctor(stri
ng)
= ( 01 00 00 00 00 )
.custom instance void
[mscorlib]System.Reflection.AssemblyTitleAttribute::.ctor(string) =
( 01 00 0C 43 46 4D 61 6E 61 67 65 64 44 4C 4C
00 // ...CFManagedDLL.
00 )

// --- The following custom attribute is added automatically, do not
uncomment -------
// .custom instance void
[mscorlib]System.Diagnostics.DebuggableAttribute::.ctor(valuetype
[mscorlib]System.Diagnostics.DebuggableAttribute/DebuggingModes) =
( 01 00 07 01 00 00 00 00 )
.hash algorithm 0x00008004
.ver 1:0:2602:17354
}
.module CFManagedDLL.dll
// MVID: {C072D8C7-8D33-477C-BB9C-275822BD1E76}
.imagebase 0x00400000
.file alignment 0x00001000
.stackreserve 0x00100000
.subsystem 0x0009 // WINDOWS_CUI
.corflags 0x00000002
.vtfixup [1] int32 fromunmanaged at VT_01
.data VT_01 = int32(0)
// Image base: 0x005F0000
// =============== CLASS MEMBERS DECLARATION ===================

.class public auto ansi beforefieldinit CFManagedDLL.Class1
extends [mscorlib]System.Object
{
.method public hidebysig static void Test() cil managed
{
.vtentry 1 : 1
.export [1] as Test
// Code size 18 (0x12)
.maxstack 8
IL_0000: nop
IL_0001: call class [mscorlib]System.IO.TextWriter
[mscorlib]System.Console::get_Out()
IL_0006: ldstr "Compact Framework Managed DLL"
IL_000b: callvirt instance void
[mscorlib]System.IO.TextWriter::WriteLine(string)
IL_0010: nop
IL_0011: ret
} // end of method Class1::Test
.method public hidebysig specialname rtspecialname
instance void .ctor() cil managed
{
// Code size 7 (0x7)
.maxstack 8
IL_0000: ldarg.0
IL_0001: call instance void
[mscorlib]System.Object::.ctor()
IL_0006: ret
} // end of method Class1::.ctor
} // end of class CFManagedDLL.Class1
Click to expand...
Click to expand...
Click to expand...
 
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