NDISwrapper

NDISwrapper

ndiswrapper command line
Developer(s) Jan Kiszka, Giridhar Pemmasani, Pontus Fuchs
Stable release
1.60 / May 1, 2016 (2016-05-01)
Operating system Linux on IA-32 and x86-64 architectures only
Type Driver wrapper
License GNU GPL
Website The NDISwrapper wiki, NDISwrapper Download Area

NDISwrapper is a free software driver wrapper that enables the use of Windows XP network device drivers (for devices such as PCI cards, USB modems, and routers) on Linux operating systems. NDISwrapper works by implementing the Windows kernel and NDIS APIs and dynamically linking Windows network drivers to this implementation. As a result, it only works on systems based on the instruction set architectures supported by Windows, namely IA-32 and x86-64.

Native drivers for some network adapters are not available on Linux as some manufacturers maintain proprietary interfaces and do not write cross-platform drivers. NDISwrapper allows the use of Windows drivers, which are available for virtually all modern PC network adapters.

Use

There are three steps: Creating a Linux driver, installing it and using it. NDISwrapper is composed of two main parts, a command-line tool used at installation time and a Windows subsystem used when an application calls the Wi-Fi subsystem.

As the outcome of an NDISwrapper installation should be some sort of Linux driver to be able to work with Linux applications, the first action the user does is to "compile" a couple or more of Windows files, and the NDISwrapper's version of Windows DDK into a Linux Kernel Module. This is done with a tool named "ndiswrapper". The resultant linux driver is then installed (often manually) in the OS. A Linux application can then send request to this Linux driver that automatically does the needed adaptations to call its—now—internal Windows driver and DDK.

To achieve this "compilation" NDISwrapper requires at least the ".inf" and the ".sys" files invariably supplied as parts of the Windows driver. For example, if the driver is called "mydriver", with the files mydriver.inf and mydriver.sys and vendorid:productid 0000:0000, then NDISwrapper installs the driver to /etc/ndiswrapper/mydriver/. This directory contains three files:

Graphical frontends

Ndisgtk graphical interface

There are graphical frontends to NDISwrapper, such as Ndisgtk and NdisConfig, which allow NDISwrapper to be installed using a graphical user interface rather than console commands.

Architecture

NDISwrapper enables a Unix-like system to use Windows drivers of type NDIS and WIFI. It was useful at a time where there were no Linux Wi-Fi drivers for common Wi-Fi cards. It works only on x86 computers because it uses Windows drivers which are only developed for x86 at the moment. It is composed of:

How it works

Ndiswrapper uses Windows INF files.[1]

When a Linux application calls a device which is registered on Linux as an NDISwrapper device, the NDISwrapper determines which Windows driver is targeted. It then converts the Linux query into Windows parlance, it calls the Windows driver, waits for the result and translates it into Linux parlance then sends the result back to the Linux application. It's possible from a Linux driver (NDISwrapper is a Linux driver) to call a Windows driver because they both execute in the same address space (the same as the Linux kernel). If the Windows driver is composed of layered drivers (for example one for Ethernet above one for USB) it's the upper layer driver which is called, and this upper layer will create new calls (IRP in Windows parlance) by calling the "mini ntoskrnl". So the "mini ntoskrnl" must know there are other drivers, it must have registered them in its internal database a priori by reading the Windows ".inf" files.

Similar programs

Limitations

While it is not a major problem for the x86 architecture because of the popularity of Windows XP x86-32, many vendors choose to make 64-bit driver versions only for Windows Vista  which means that Linux systems using the x86-64 architecture are unable to use such networking devices (they can neither use XP x86-32 NDIS5 because they are 64bits systems nor NDIS6 64bit drivers because they can't use NDIS6). It's still possible to use Windows XP 64 bit drivers which implement NDIS5,[8] however, there are fewer available drivers for xp64 (NDIS5/64 bit) than for XP32 (NDIS5/32 bit).

See also

References

This article is issued from Wikipedia - version of the 12/3/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.