dist/wpa/wpa_supplicant/doc/docbook/wpa_supplicant.sgml

   1 <!doctype refentry PUBLIC "-//OASIS//DTD DocBook V4.1//EN">
   2
   3 <refentry>
   4   <refmeta>
   5     <refentrytitle>wpa_supplicant</refentrytitle>
   6     <manvolnum>8</manvolnum>
   7   </refmeta>
   8   <refnamediv>
   9     <refname>wpa_supplicant</refname>
  10     <refpurpose>Wi-Fi Protected Access client and IEEE 802.1X supplicant</refpurpose>
  11   </refnamediv>
  12   <refsynopsisdiv>
  13     <cmdsynopsis>
  14       <command>wpa_supplicant</command>
  15       <arg>-BddfhKLqqtuvW</arg>
  16       <arg>-i<replaceable>ifname</replaceable></arg>
  17       <arg>-c<replaceable>config file</replaceable></arg>
  18       <arg>-D<replaceable>driver</replaceable></arg>
  19       <arg>-P<replaceable>PID_file</replaceable></arg>
  20       <arg>-f<replaceable>output file</replaceable></arg>
  21     </cmdsynopsis>
  22   </refsynopsisdiv>
  23   <refsect1>
  24     <title>Overview</title>
  25
  26     <para>
  27     Wireless networks do not require physical access to the network equipment
  28     in the same way as wired networks. This makes it easier for unauthorized
  29     users to passively monitor a network and capture all transmitted frames.
  30     In addition, unauthorized use of the network is much easier. In many cases,
  31     this can happen even without user's explicit knowledge since the wireless
  32     LAN adapter may have been configured to automatically join any available
  33     network.
  34     </para>
  35
  36     <para>
  37     Link-layer encryption can be used to provide a layer of security for
  38     wireless networks. The original wireless LAN standard, IEEE 802.11,
  39     included a simple encryption mechanism, WEP. However, that proved to
  40     be flawed in many areas and network protected with WEP cannot be consider
  41     secure. IEEE 802.1X authentication and frequently changed dynamic WEP keys
  42     can be used to improve the network security, but even that has inherited
  43     security issues due to the use of WEP for encryption. Wi-Fi Protected
  44     Access and IEEE 802.11i amendment to the wireless LAN standard introduce
  45     a much improvement mechanism for securing wireless networks. IEEE 802.11i
  46     enabled networks that are using CCMP (encryption mechanism based on strong
  47     cryptographic algorithm AES) can finally be called secure used for
  48     applications which require efficient protection against unauthorized
  49     access.
  50     </para>
  51
  52     <para><command>wpa_supplicant</command> is an implementation of
  53     the WPA Supplicant component, i.e., the part that runs in the
  54     client stations. It implements WPA key negotiation with a WPA
  55     Authenticator and EAP authentication with Authentication
  56     Server. In addition, it controls the roaming and IEEE 802.11
  57     authentication/association of the wireless LAN driver.</para>
  58
  59     <para><command>wpa_supplicant</command> is designed to be a
  60     "daemon" program that runs in the background and acts as the
  61     backend component controlling the wireless
  62     connection. <command>wpa_supplicant</command> supports separate
  63     frontend programs and an example text-based frontend,
  64     <command>wpa_cli</command>, is included with
  65     wpa_supplicant.</para>
  66
  67     <para>Before wpa_supplicant can do its work, the network interface
  68     must be available.  That means that the physical device must be
  69     present and enabled, and the driver for the device must have be
  70     loaded. The daemon will exit immediately if the device is not already
  71     available.</para>
  72
  73     <para>After <command>wpa_supplicant</command> has configured the
  74     network device, higher level configuration such as DHCP may
  75     proceed.  There are a variety of ways to integrate wpa_supplicant
  76     into a machine's networking scripts, a few of which are described
  77     in sections below.</para>
  78
  79     <para>The following steps are used when associating with an AP
  80     using WPA:</para>
  81
  82     <itemizedlist>
  83       <listitem>
  84         <para><command>wpa_supplicant</command> requests the kernel
  85         driver to scan neighboring BSSes</para>
  86       </listitem>
  87
  88       <listitem>
  89         <para><command>wpa_supplicant</command> selects a BSS based on
  90         its configuration</para>
  91       </listitem>
  92
  93       <listitem>
  94         <para><command>wpa_supplicant</command> requests the kernel
  95         driver to associate with the chosen BSS</para>
  96       </listitem>
  97
  98       <listitem>
  99         <para>If WPA-EAP: integrated IEEE 802.1X Supplicant
 100         completes EAP authentication with the
 101         authentication server (proxied by the Authenticator in the
 102         AP)</para>
 103       </listitem>
 104
 105       <listitem>
 106         <para>If WPA-EAP: master key is received from the IEEE 802.1X
 107         Supplicant</para>
 108       </listitem>
 109
 110       <listitem>
 111         <para>If WPA-PSK: <command>wpa_supplicant</command> uses PSK
 112         as the master session key</para>
 113       </listitem>
 114
 115       <listitem>
 116         <para><command>wpa_supplicant</command> completes WPA 4-Way
 117         Handshake and Group Key Handshake with the Authenticator
 118         (AP)</para>
 119       </listitem>
 120
 121       <listitem>
 122         <para><command>wpa_supplicant</command> configures encryption
 123         keys for unicast and broadcast</para>
 124       </listitem>
 125
 126       <listitem>
 127         <para>normal data packets can be transmitted and received</para>
 128       </listitem>
 129     </itemizedlist>
 130   </refsect1>
 131
 132   <refsect1>
 133     <title>Supported Features</title>
 134     <para>Supported WPA/IEEE 802.11i features:</para>
 135     <itemizedlist>
 136       <listitem>
 137         <para>WPA-PSK ("WPA-Personal")</para>
 138       </listitem>
 139
 140       <listitem>
 141         <para>WPA with EAP (e.g., with RADIUS authentication server)
 142        ("WPA-Enterprise") Following authentication methods are
 143        supported with an integrate IEEE 802.1X Supplicant:</para>
 144
 145         <itemizedlist>
 146           <listitem>
 147             <para>EAP-TLS</para>
 148           </listitem>
 149         </itemizedlist>
 150
 151         <itemizedlist>
 152           <listitem>
 153             <para>EAP-PEAP/MSCHAPv2 (both PEAPv0 and PEAPv1)</para>
 154           </listitem>
 155
 156
 157           <listitem>
 158             <para>EAP-PEAP/TLS (both PEAPv0 and PEAPv1)</para>
 159           </listitem>
 160
 161           <listitem>
 162             <para>EAP-PEAP/GTC (both PEAPv0 and PEAPv1)</para>
 163           </listitem>
 164
 165           <listitem>
 166             <para>EAP-PEAP/OTP (both PEAPv0 and PEAPv1)</para>
 167           </listitem>
 168
 169           <listitem>
 170             <para>EAP-PEAP/MD5-Challenge (both PEAPv0 and PEAPv1)</para>
 171           </listitem>
 172
 173           <listitem>
 174             <para>EAP-TTLS/EAP-MD5-Challenge</para>
 175           </listitem>
 176
 177           <listitem>
 178             <para>EAP-TTLS/EAP-GTC</para>
 179           </listitem>
 180
 181           <listitem><para>EAP-TTLS/EAP-OTP</para></listitem>
 182
 183           <listitem><para>EAP-TTLS/EAP-MSCHAPv2</para></listitem>
 184
 185           <listitem><para>EAP-TTLS/EAP-TLS</para></listitem>
 186
 187           <listitem><para>EAP-TTLS/MSCHAPv2</para></listitem>
 188
 189           <listitem><para>EAP-TTLS/MSCHAP</para></listitem>
 190
 191           <listitem><para>EAP-TTLS/PAP</para></listitem>
 192
 193           <listitem><para>EAP-TTLS/CHAP</para></listitem>
 194
 195           <listitem><para>EAP-SIM</para></listitem>
 196
 197           <listitem><para>EAP-AKA</para></listitem>
 198
 199           <listitem><para>EAP-PSK</para></listitem>
 200
 201           <listitem><para>EAP-PAX</para></listitem>
 202
 203           <listitem><para>LEAP (note: requires special support from
 204           the driver for IEEE 802.11 authentication)</para></listitem>
 205
 206           <listitem><para>(following methods are supported, but since
 207           they do not generate keying material, they cannot be used
 208           with WPA or IEEE 802.1X WEP keying)</para></listitem>
 209
 210           <listitem><para>EAP-MD5-Challenge </para></listitem>
 211
 212           <listitem><para>EAP-MSCHAPv2</para></listitem>
 213
 214           <listitem><para>EAP-GTC</para></listitem>
 215
 216           <listitem><para>EAP-OTP</para></listitem>
 217         </itemizedlist>
 218       </listitem>
 219
 220       <listitem>
 221         <para>key management for CCMP, TKIP, WEP104, WEP40</para>
 222       </listitem>
 223
 224       <listitem>
 225         <para>RSN/WPA2 (IEEE 802.11i)</para>
 226         <itemizedlist>
 227           <listitem>
 228             <para>pre-authentication</para>
 229           </listitem>
 230
 231           <listitem>
 232             <para>PMKSA caching</para>
 233           </listitem>
 234         </itemizedlist>
 235       </listitem>
 236     </itemizedlist>
 237   </refsect1>
 238
 239   <refsect1>
 240     <title>Available Drivers</title>
 241     <para>A summary of available driver backends is below. Support for each
 242     of the driver backends is chosen at wpa_supplicant compile time. For a
 243     list of supported driver backends that may be used with the -D option on
 244     your system, refer to the help output of wpa_supplicant
 245     (<emphasis>wpa_supplicant -h</emphasis>).</para>
 246
 247     <variablelist>
 248       <varlistentry>
 249         <term>hostap</term>
 250         <listitem>
 251           <para>(default) Host AP driver (Intersil Prism2/2.5/3).
 252           (this can also be used with Linuxant DriverLoader).</para>
 253         </listitem>
 254       </varlistentry>
 255
 256       <varlistentry>
 257         <term>hermes</term>
 258         <listitem>
 259           <para>Agere Systems Inc. driver (Hermes-I/Hermes-II).</para>
 260         </listitem>
 261       </varlistentry>
 262
 263       <varlistentry>
 264         <term>madwifi</term>
 265         <listitem>
 266           <para>MADWIFI 802.11 support (Atheros, etc.).</para>
 267         </listitem>
 268       </varlistentry>
 269
 270       <varlistentry>
 271         <term>atmel</term>
 272         <listitem>
 273           <para>ATMEL AT76C5XXx (USB, PCMCIA).</para>
 274         </listitem>
 275       </varlistentry>
 276
 277       <varlistentry>
 278         <term>wext</term>
 279         <listitem>
 280           <para>Linux wireless extensions (generic).</para>
 281         </listitem>
 282       </varlistentry>
 283
 284       <varlistentry>
 285         <term>ndiswrapper</term>
 286         <listitem>
 287           <para>Linux ndiswrapper.</para>
 288         </listitem>
 289       </varlistentry>
 290
 291       <varlistentry>
 292         <term>broadcom</term>
 293         <listitem>
 294           <para>Broadcom wl.o driver.</para>
 295         </listitem>
 296       </varlistentry>
 297
 298       <varlistentry>
 299         <term>ipw</term>
 300         <listitem>
 301           <para>Intel ipw2100/2200 driver.</para>
 302         </listitem>
 303       </varlistentry>
 304
 305       <varlistentry>
 306         <term>wired</term>
 307         <listitem>
 308           <para>wpa_supplicant wired Ethernet driver</para>
 309         </listitem>
 310       </varlistentry>
 311
 312       <varlistentry>
 313         <term>bsd</term>
 314         <listitem>
 315           <para>BSD 802.11 support (Atheros, etc.).</para>
 316         </listitem>
 317       </varlistentry>
 318
 319       <varlistentry>
 320         <term>ndis</term>
 321         <listitem>
 322           <para>Windows NDIS driver.</para>
 323         </listitem>
 324       </varlistentry>
 325     </variablelist>
 326   </refsect1>
 327
 328   <refsect1>
 329     <title>Command Line Options</title>
 330     <para>Most command line options have global scope. Some are given per
 331     interface, and are only valid if at least one <option>-i</option> option
 332     is specified, otherwise they're ignored. Option groups for different
 333     interfaces must be separated by <option>-N</option> option.</para>
 334     <variablelist>
 335       <varlistentry>
 336         <term>-b br_ifname</term>
 337         <listitem>
 338           <para>Optional bridge interface name. (Per interface)</para>
 339         </listitem>
 340       </varlistentry>
 341
 342       <varlistentry>
 343         <term>-B</term>
 344         <listitem>
 345           <para>Run daemon in the background.</para>
 346         </listitem>
 347       </varlistentry>
 348
 349       <varlistentry>
 350         <term>-c filename</term>
 351         <listitem>
 352           <para>Path to configuration file. (Per interface)</para>
 353         </listitem>
 354       </varlistentry>
 355
 356       <varlistentry>
 357         <term>-C ctrl_interface</term>
 358         <listitem>
 359           <para>Path to ctrl_interface socket (Per interface. Only used if
 360                   <option>-c</option> is not).</para>
 361         </listitem>
 362       </varlistentry>
 363
 364       <varlistentry>
 365         <term>-i ifname</term>
 366         <listitem>
 367           <para>Interface to listen on. Multiple instances of this option can
 368           be present, one per interface, separated by <option>-N</option>
 369           option (see below).</para>
 370         </listitem>
 371       </varlistentry>
 372
 373       <varlistentry>
 374         <term>-d</term>
 375         <listitem>
 376           <para>Increase debugging verbosity (<option>-dd</option> even
 377                   more).</para>
 378         </listitem>
 379       </varlistentry>
 380
 381       <varlistentry>
 382         <term>-D driver</term>
 383         <listitem>
 384           <para>Driver to use. (Per interface, see the available options
 385                   below.)</para>
 386         </listitem>
 387       </varlistentry>
 388
 389       <varlistentry>
 390         <term>-f output file</term>
 391         <listitem>
 392           <para>Log output to specified file instead of stdout.</para>
 393         </listitem>
 394       </varlistentry>
 395
 396       <varlistentry>
 397         <term>-g global ctrl_interface</term>
 398         <listitem>
 399           <para>Path to global ctrl_interface socket. If specified, interface
 400           definitions may be omitted.</para>
 401         </listitem>
 402       </varlistentry>
 403
 404       <varlistentry>
 405         <term>-K</term>
 406         <listitem>
 407           <para>Include keys (passwords, etc.) in debug output.</para>
 408         </listitem>
 409       </varlistentry>
 410
 411       <varlistentry>
 412         <term>-t</term>
 413         <listitem>
 414           <para>Include timestamp in debug messages.</para>
 415         </listitem>
 416       </varlistentry>
 417
 418       <varlistentry>
 419         <term>-h</term>
 420         <listitem>
 421           <para>Help.  Show a usage message.</para>
 422         </listitem>
 423       </varlistentry>
 424
 425       <varlistentry>
 426         <term>-L</term>
 427         <listitem>
 428           <para>Show license (GPL and BSD).</para>
 429         </listitem>
 430       </varlistentry>
 431
 432       <varlistentry>
 433         <term>-p</term>
 434         <listitem>
 435           <para>Driver parameters. (Per interface)</para>
 436         </listitem>
 437       </varlistentry>
 438
 439       <varlistentry>
 440         <term>-P PID_file</term>
 441         <listitem>
 442           <para>Path to PID file.</para>
 443         </listitem>
 444       </varlistentry>
 445
 446       <varlistentry>
 447         <term>-q</term>
 448         <listitem>
 449           <para>Decrease debugging verbosity (<option>-qq</option> even
 450                   less).</para>
 451         </listitem>
 452       </varlistentry>
 453
 454       <varlistentry>
 455         <term>-u</term>
 456         <listitem>
 457           <para>Enabled DBus control interface. If enabled, interface
 458           definitions may be omitted.</para>
 459         </listitem>
 460       </varlistentry>
 461
 462       <varlistentry>
 463         <term>-v</term>
 464         <listitem>
 465           <para>Show version.</para>
 466         </listitem>
 467       </varlistentry>
 468
 469       <varlistentry>
 470         <term>-W</term>
 471         <listitem>
 472           <para>Wait for a control interface monitor before starting.</para>
 473         </listitem>
 474       </varlistentry>
 475
 476       <varlistentry>
 477         <term>-N</term>
 478         <listitem>
 479           <para>Start describing new interface.</para>
 480         </listitem>
 481       </varlistentry>
 482     </variablelist>
 483   </refsect1>
 484
 485   <refsect1>
 486     <title>Examples</title>
 487
 488     <para>In most common cases, <command>wpa_supplicant</command> is
 489     started with:</para>
 490
 491 <blockquote><programlisting>
 492 wpa_supplicant -B -c/etc/wpa_supplicant.conf -iwlan0
 493 </programlisting></blockquote>
 494
 495     <para>This makes the process fork into background.</para>
 496
 497     <para>The easiest way to debug problems, and to get debug log for
 498     bug reports, is to start <command>wpa_supplicant</command> on
 499     foreground with debugging enabled:</para>
 500
 501 <blockquote><programlisting>
 502 wpa_supplicant -c/etc/wpa_supplicant.conf -iwlan0 -d
 503 </programlisting></blockquote>
 504
 505     <para><command>wpa_supplicant</command> can control multiple
 506     interfaces (radios) either by running one process for each
 507     interface separately or by running just one process and list of
 508     options at command line. Each interface is separated with -N
 509     argument. As an example, following command would start
 510     wpa_supplicant for two interfaces:</para>
 511
 512 <blockquote><programlisting>
 513 wpa_supplicant \
 514         -c wpa1.conf -i wlan0 -D hostap -N \
 515         -c wpa2.conf -i ath0 -D madwifi
 516 </programlisting></blockquote>
 517   </refsect1>
 518
 519   <refsect1>
 520     <title>OS Requirements</title>
 521     <para>Current hardware/software requirements:</para>
 522
 523     <itemizedlist>
 524       <listitem>
 525         <para>Linux kernel 2.4.x or 2.6.x with Linux Wireless
 526         Extensions v15 or newer</para>
 527       </listitem>
 528
 529
 530       <listitem>
 531         <para>FreeBSD 6-CURRENT</para>
 532       </listitem>
 533
 534       <listitem>
 535         <para>Microsoft Windows with WinPcap (at least WinXP, may work
 536         with other versions)</para>
 537       </listitem>
 538     </itemizedlist>
 539   </refsect1>
 540
 541   <refsect1>
 542     <title>Supported Drivers</title>
 543     <variablelist>
 544       <varlistentry>
 545         <term>Host AP driver for Prism2/2.5/3 (development
 546         snapshot/v0.2.x)</term>
 547         <listitem>
 548           <para> (http://hostap.epitest.fi/) Driver needs to be set in
 549           Managed mode (<emphasis>iwconfig wlan0 mode managed</emphasis>).
 550           Please note that station firmware version needs to be 1.7.0 or
 551           newer to work in WPA mode.</para>
 552         </listitem>
 553       </varlistentry>
 554
 555       <varlistentry>
 556         <term>Linuxant DriverLoader</term>
 557         <listitem>
 558           <para>(http://www.linuxant.com/driverloader/)
 559         with Windows NDIS driver for your wlan card supporting WPA.</para>
 560         </listitem>
 561       </varlistentry>
 562
 563       <varlistentry>
 564         <term>Agere Systems Inc. Linux Driver</term>
 565         <listitem>
 566           <para> (http://www.agere.com/support/drivers/) Please note
 567         that the driver interface file (driver_hermes.c) and hardware
 568         specific include files are not included in the wpa_supplicant
 569         distribution. You will need to copy these from the source
 570         package of the Agere driver.</para>
 571         </listitem>
 572       </varlistentry>
 573
 574       <varlistentry>
 575         <term>madwifi driver for cards based on Atheros chip set (ar521x)</term>
 576         <listitem>
 577           <para> (http://sourceforge.net/projects/madwifi/) Please
 578         note that you will need to modify the wpa_supplicant .config
 579         file to use the correct path for the madwifi driver root
 580         directory (CFLAGS += -I../madwifi/wpa line in example
 581         defconfig).</para>
 582         </listitem>
 583       </varlistentry>
 584
 585       <varlistentry>
 586         <term>ATMEL AT76C5XXx driver for USB and PCMCIA cards</term>
 587         <listitem>
 588           <para> (http://atmelwlandriver.sourceforge.net/).</para>
 589         </listitem>
 590       </varlistentry>
 591
 592       <varlistentry>
 593         <term>Linux ndiswrapper</term>
 594         <listitem>
 595           <para> (http://ndiswrapper.sourceforge.net/) with Windows
 596         NDIS driver.</para>
 597         </listitem>
 598       </varlistentry>
 599
 600       <varlistentry>
 601         <term>Broadcom wl.o driver</term>
 602         <listitem>
 603           <para> This is a generic Linux driver for Broadcom IEEE
 604         802.11a/g cards.  However, it is proprietary driver that is
 605         not publicly available except for couple of exceptions, mainly
 606         Broadcom-based APs/wireless routers that use Linux. The driver
 607         binary can be downloaded, e.g., from Linksys support site
 608         (http://www.linksys.com/support/gpl.asp) for Linksys
 609         WRT54G. The GPL tarball includes cross-compiler and the needed
 610         header file, wlioctl.h, for compiling wpa_supplicant.  This
 611         driver support in wpa_supplicant is expected to work also with
 612         other devices based on Broadcom driver (assuming the driver
 613         includes client mode support).</para>
 614         </listitem>
 615       </varlistentry>
 616
 617       <varlistentry>
 618         <term> Intel ipw2100 driver</term>
 619         <listitem>
 620           <para> (http://sourceforge.net/projects/ipw2100/)</para>
 621         </listitem>
 622       </varlistentry>
 623
 624       <varlistentry>
 625         <term>Intel ipw2200 driver</term>
 626         <listitem>
 627           <para> (http://sourceforge.net/projects/ipw2200/)</para>
 628         </listitem>
 629       </varlistentry>
 630
 631       <varlistentry>
 632         <term>Linux wireless extensions</term>
 633         <listitem>
 634           <para>In theory, any driver that supports Linux wireless
 635         extensions can be used with IEEE 802.1X (i.e., not WPA) when
 636         using ap_scan=0 option in configuration file.</para>
 637         </listitem>
 638       </varlistentry>
 639
 640       <varlistentry>
 641         <term>Wired Ethernet drivers</term>
 642         <listitem>
 643           <para>Use ap_scan=0.</para>
 644         </listitem>
 645       </varlistentry>
 646
 647       <varlistentry>
 648         <term>BSD net80211 layer (e.g., Atheros driver)</term>
 649         <listitem>
 650           <para>At the moment, this is for FreeBSD 6-CURRENT branch.</para>
 651         </listitem>
 652       </varlistentry>
 653
 654       <varlistentry>
 655         <term>Windows NDIS</term>
 656         <listitem>
 657           <para>The current Windows port requires WinPcap
 658         (http://winpcap.polito.it/).  See README-Windows.txt for more
 659         information.</para>
 660         </listitem>
 661       </varlistentry>
 662     </variablelist>
 663
 664
 665     <para>wpa_supplicant was designed to be portable for different
 666     drivers and operating systems. Hopefully, support for more wlan
 667     cards and OSes will be added in the future. See developer.txt for
 668     more information about the design of wpa_supplicant and porting to
 669     other drivers. One main goal is to add full WPA/WPA2 support to
 670     Linux wireless extensions to allow new drivers to be supported
 671     without having to implement new driver-specific interface code in
 672     wpa_supplicant.</para>
 673   </refsect1>
 674
 675   <refsect1>
 676     <title>Architecture</title> <para>The
 677     <command>wpa_supplicant</command> system consists of the following
 678     components:</para>
 679
 680     <variablelist>
 681       <varlistentry>
 682         <term><filename>wpa_supplicant.conf</filename> </term>
 683         <listitem>
 684         <para>the configuration file describing all networks that the
 685         user wants the computer to connect to.  </para>
 686         </listitem>
 687       </varlistentry>
 688       <varlistentry>
 689         <term><command>wpa_supplicant</command></term>
 690         <listitem><para>the program that directly interacts with the
 691         network interface.  </para></listitem>
 692       </varlistentry>
 693       <varlistentry>
 694         <term><command>wpa_cli</command></term> <listitem><para> the
 695         client program that provides a high-level interface to the
 696         functionality of the daemon.  </para></listitem>
 697       </varlistentry>
 698       <varlistentry>
 699         <term><command>wpa_passphrase</command></term>
 700         <listitem><para>a utility needed to construct
 701         <filename>wpa_supplicant.conf</filename> files that include
 702         encrypted passwords.</para></listitem>
 703       </varlistentry>
 704     </variablelist>
 705   </refsect1>
 706
 707   <refsect1>
 708     <title>Quick Start</title>
 709
 710     <para>First, make a configuration file, e.g.
 711     <filename>/etc/wpa_supplicant.conf</filename>, that describes the networks
 712     you are interested in.  See <citerefentry>
 713         <refentrytitle>wpa_supplicant.conf</refentrytitle>
 714         <manvolnum>5</manvolnum>
 715       </citerefentry>
 716     for details.</para>
 717
 718     <para>Once the configuration is ready, you can test whether the
 719     configuration works by running <command>wpa_supplicant</command>
 720     with following command to start it on foreground with debugging
 721     enabled:</para>
 722
 723     <blockquote><programlisting>
 724 wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -d
 725     </programlisting></blockquote>
 726
 727     <para>Assuming everything goes fine, you can start using following
 728     command to start <command>wpa_supplicant</command> on background
 729     without debugging:</para>
 730
 731     <blockquote><programlisting>
 732 wpa_supplicant -iwlan0 -c/etc/wpa_supplicant.conf -B
 733     </programlisting></blockquote>
 734
 735     <para>Please note that if you included more than one driver
 736     interface in the build time configuration (.config), you may need
 737     to specify which interface to use by including -D&lt;driver
 738     name&gt; option on the command line.</para>
 739
 740     <!-- XXX at this point, the page could include a little script
 741          based on wpa_cli to wait for a connection and then run
 742          dhclient -->
 743
 744   </refsect1>
 745
 746   <refsect1>
 747     <title>Interface to pcmcia-cs/cardmrg</title>
 748
 749     <para>For example, following small changes to pcmcia-cs scripts
 750     can be used to enable WPA support:</para>
 751
 752     <para>Add MODE="Managed" and WPA="y" to the network scheme in
 753     <filename>/etc/pcmcia/wireless.opts</filename>.</para>
 754
 755     <para>Add the following block to the end of <emphasis>start</emphasis>
 756     action handler in <filename>/etc/pcmcia/wireless</filename>:</para>
 757
 758     <blockquote><programlisting>
 759 if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then
 760     /usr/local/bin/wpa_supplicant -B -c/etc/wpa_supplicant.conf -i$DEVICE
 761 fi
 762     </programlisting></blockquote>
 763
 764
 765     <para>Add the following block to the end of <emphasis>stop</emphasis>
 766     action handler (may need to be separated from other actions) in
 767     <filename>/etc/pcmcia/wireless</filename>:</para>
 768
 769     <blockquote><programlisting>
 770 if [ "$WPA" = "y" -a -x /usr/local/bin/wpa_supplicant ]; then
 771     killall wpa_supplicant
 772 fi
 773     </programlisting></blockquote>
 774
 775     <para>This will make <command>cardmgr</command> start
 776     <command>wpa_supplicant</command> when the card is plugged
 777     in.</para>
 778   </refsect1>
 779
 780   <refsect1>
 781     <title>See Also</title>
 782     <para>
 783       <citerefentry>
 784         <refentrytitle>wpa_background</refentrytitle>
 785         <manvolnum>8</manvolnum>
 786       </citerefentry>
 787       <citerefentry>
 788         <refentrytitle>wpa_supplicant.conf</refentrytitle>
 789         <manvolnum>5</manvolnum>
 790       </citerefentry>
 791       <citerefentry>
 792         <refentrytitle>wpa_cli</refentrytitle>
 793         <manvolnum>8</manvolnum>
 794       </citerefentry>
 795       <citerefentry>
 796         <refentrytitle>wpa_passphrase</refentrytitle>
 797         <manvolnum>8</manvolnum>
 798       </citerefentry>
 799     </para>
 800   </refsect1>
 801   <refsect1>
 802     <title>Legal</title>
 803     <para>wpa_supplicant is copyright (c) 2003-2007,
 804     Jouni Malinen <email>j@w1.fi</email> and
 805     contributors.
 806     All Rights Reserved.</para>
 807
 808     <para>This program is dual-licensed under both the GPL version 2
 809     and BSD license. Either license may be used at your option.</para>
 810   </refsect1>
 811 </refentry>