hostap

http://hostap.epitest.fi/

hostapd - user space daemon for access points, including, e.g., IEEE 802.1X/WPA/EAP Authenticator for number of Linux and BSD drivers, RADIUS client, integrated EAP server, and RADIUS authentication server

wpa_supplicant user space IEEE 802.1X/WPA supplicant (wireless client) for number of Linux, BSD, and Windows drivers

Host AP driver for Intersil Prism2/2.5/3

Host AP is a Linux driverfor wireless LAN cards based on Intersil's Prism2/2.5/3 chipset. The driver supports a so called Host AP mode, i.e., it takes care of IEEE 802.11 management functions in the host computer and acts as an access point.This does not require any special firmware for the wireless LAN card. In addition to this, it has support for normal station operations in BSS andpossible also in IBSS. WPA and RSN (WPA2) is supported when used with accompanied tools, wpa_supplicant (WPA/RSN Supplicant) and hostapd (WPA/RSN Authenticator). All these programs have been designed for both desktop/laptop computers and embedded systems.

Intersil's station firmware for Prism2 chipset supports aso called Host AP mode in which the firmware takes care of time critical tasks like beacon sending and frame acknowledging,but leaves other management tasks to host computer driver.This driver implements basic functionality needed to initialize and configure Prism2-based cards, to send and receive frames, and to gather statistics. In addition,it includes an implementation of following IEEE 802.11 functions: authentication (and deauthentication), association (reassociation, and disassociation), data transmission between two wireless stations, power saving (PS) mode signaling and frame buffering for PS stations.The driver has also various features for development debugging and for researching IEEE 802.11 environments like access to hardware configuration records, I/O registers, and frames with 802.11 headers.

When used with a user space daemon, the combination of the Host AP driver and hostapd daemon includes additional features. These include support for IEEE 802.1X and dynamic WEP rekeying, RADIUS Accounting, RADIUS-based ACL for IEEE 802.11 authentication, minimal IAPP (IEEE 802.11f), WPA, IEEE 802.11i/RSN/WPA2.

Linux Wireless LAN Howto has some useful information about wireless LAN support in Linux. In addition, it includes information about which cards are Prism2-based (and can thus be used in Host AP mode).