1mac80211_hwsim - software simulator of 802.11 radio(s) for mac80211 2Copyright (c) 2008, Jouni Malinen <j@w1.fi> 3 4This program is free software; you can redistribute it and/or modify 5it under the terms of the GNU General Public License version 2 as 6published by the Free Software Foundation. 7 8 9Introduction 10 11mac80211_hwsim is a Linux kernel module that can be used to simulate 12arbitrary number of IEEE 802.11 radios for mac80211. It can be used to 13test most of the mac80211 functionality and user space tools (e.g., 14hostapd and wpa_supplicant) in a way that matches very closely with 15the normal case of using real WLAN hardware. From the mac80211 view 16point, mac80211_hwsim is yet another hardware driver, i.e., no changes 17to mac80211 are needed to use this testing tool. 18 19The main goal for mac80211_hwsim is to make it easier for developers 20to test their code and work with new features to mac80211, hostapd, 21and wpa_supplicant. The simulated radios do not have the limitations 22of real hardware, so it is easy to generate an arbitrary test setup 23and always reproduce the same setup for future tests. In addition, 24since all radio operation is simulated, any channel can be used in 25tests regardless of regulatory rules. 26 27mac80211_hwsim kernel module has a parameter 'radios' that can be used 28to select how many radios are simulated (default 2). This allows 29configuration of both very simply setups (e.g., just a single access 30point and a station) or large scale tests (multiple access points with 31hundreds of stations). 32 33mac80211_hwsim works by tracking the current channel of each virtual 34radio and copying all transmitted frames to all other radios that are 35currently enabled and on the same channel as the transmitting 36radio. Software encryption in mac80211 is used so that the frames are 37actually encrypted over the virtual air interface to allow more 38complete testing of encryption. 39 40A global monitoring netdev, hwsim#, is created independent of 41mac80211. This interface can be used to monitor all transmitted frames 42regardless of channel. 43 44 45Simple example 46 47This example shows how to use mac80211_hwsim to simulate two radios: 48one to act as an access point and the other as a station that 49associates with the AP. hostapd and wpa_supplicant are used to take 50care of WPA2-PSK authentication. In addition, hostapd is also 51processing access point side of association. 52 53 54# Build mac80211_hwsim as part of kernel configuration 55 56# Load the module 57modprobe mac80211_hwsim 58 59# Run hostapd (AP) for wlan0 60hostapd hostapd.conf 61 62# Run wpa_supplicant (station) for wlan1 63wpa_supplicant -Dwext -iwlan1 -c wpa_supplicant.conf 64 65 66More test cases are available in hostap.git: 67git://w1.fi/srv/git/hostap.git and mac80211_hwsim/tests subdirectory 68(http://w1.fi/gitweb/gitweb.cgi?p=hostap.git;a=tree;f=mac80211_hwsim/tests) 69