On Tue, 2008-06-10 at 13:50 +0300, Jouni Malinen wrote: > hostapd and wpa_supplicant include a test driver interface that allows > them to be tested on a single host without any wireless hardware for > development purposes. I have found this very valuable both for > developing new functionality and for testing existing code. > > In order to provide similar mechanism for mac80211 developers and to > extend the scope of suitable test cases for hostapd/wpa_supplicant, I've > written a Linux kernel module that provides a similar test interface at > a lower layer. mac80211_hwsim simulates WLAN hardware and the air > interface between the radios by acting as a low-level radio driver for > mac80211. Neither mac80211 nor user space programs need any changes to > work with the simulated radios. Awesome. I was going to write a basic WEXT driver so I could get some better tests going for NetworkManager, but you've beaten me to it :) Thanks! Dan > The initial version of mac80211_hwsim is available from the > mac80211_hwsim subdirectory of my hostap Git tree: > git://w1.fi/srv/git/hostap.git > http://w1.fi/gitweb/gitweb.cgi?p=hostap.git;a=tree;f=mac80211_hwsim > > If there is interest in moving mac80211_hwsim module into the Linux > kernel tree, I'm open to doing that, too. > > I've included some more information about the code in the README file > (see below) and there are also example configuration files for hostapd > and wpa_supplicant to show how a WPA2-Personal connection can be opened > with mac80211_hwsim. > > mac80211_hwsim is still very minimal, but I have added couple of TODO > comments to the source code to indicate areas that I'm hoping to add for > more complete support of mac80211 features. I would also be interested > in feedback from other mac80211 developers on what kind of functionality > would be useful to have in this kind of simulated test setup. I'm first > looking into using this to develop IEEE 802.11w (management frame > protection) support into mac80211 and I would expect that the current > minimal design is enough for that, but there is certainly room for much > more, e.g., in the area of simulating signal strength and packet loss > for testing TX rate control, retransmission, and power save > functionality. > > > > README: > > Introduction > > mac80211_hwsim is a Linux kernel module that can be used to simulate > arbitrary number of IEEE 802.11 radios for mac80211 on a single > device. It can be used to test most of the mac80211 functionality and > user space tools (e.g., hostapd and wpa_supplicant) in a way that > matches very closely with the normal case of using real WLAN > hardware. From the mac80211 view point, mac80211_hwsim is yet another > hardware driver, i.e., no changes to mac80211 are needed to use this > testing tool. > > The main goal for mac80211_hwsim is to make it easier for developers > to test their code and work with new features to mac80211, hostapd, > and wpa_supplicant. The simulated radios do not have the limitations > of real hardware, so it is easy to generate an arbitrary test setup > and always reproduce the same setup for future tests. In addition, > since all radio operation is simulated, any channel can be used in > tests regardless of regulatory rules. > > mac80211_hwsim kernel module has a parameter 'radios' that can be used > to select how many radios are simulates (default 2). This allows > configuration of both very simply setups (e.g., just a single access > point and a station) or large scale tests (multiple access points with > hundreds of stations). > > mac80211_hwsim works by tracking the current channel of each virtual > radio and copying all transmitted frames to all other radios that are > currently enabled and on the same channel as the transmitting > radio. Software encryption in mac80211 is used so that the frames are > actually encrypted over the virtual air interface to allow more > complete testing of encryption. > > > Simple example > > This example shows how to use mac80211_hwsim to simulate two radios: > one to act as an access point and the other as a station that > associates with the AP. hostapd and wpa_supplicant are used to take > care of WPA2-PSK authentication. In addition, hostapd is also > processing access point side of association. > > Please note that the currently released Linux kernel (2.6.25) does not > enable AP mode, so a simple patch is needed to enable AP mode selection: > http://johannes.sipsolutions.net/patches/kernel/all/LATEST/006-allow-ap-vlan-modes.patch > > > # Build mac80211_hwsim: > make > > # Load the module > insmod ./mac80211_hwsim.ko > > # Run hostapd (AP) for wlan0 > hostapd hostapd.conf > > # Run wpa_supplicant (station) for wlan1 > wpa_supplicant -Dwext -iwlan1 -c wpa_supplicant.conf > -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
