本文介绍了嵌入式ARM-Linux上的常用应用程序wpa_supplicant(以及wpa_supplicant依赖的libnl和openssl)的编译、配置和运行使用，iw、hostapd等应用的编译和使用。

wpa_supplicant 编译和配置运行

从https://w1.fi/wpa_supplicant/ (git地址git://w1.fi/hostap.git)下载最新的wpa_supplicant源码压缩包，目前最新的为版本2.5. wpa_supplicant的编译依赖于openssl和libnl库(Netlink Protocol Library Suite (libnl))，openssl是ssl协议的开源库(OpenSSL , Secure Sockets Layer (SSL v2/v3) Transport Layer Security (TLS v1)).(压缩包地址：http://www.openssl.org/source/ ，Git地址：https://github.com/openssl/openssl )，libnl是网络相关的库(压缩包地址：http://www.infradead.org/~tgr/libnl/ ， Git地址 ： http://git.infradead.org/users/tgr/libnl.git)。

编译libnl

解压源代码包。进入libnl目录，执行 ./configure 配置编译环境；执行make进行编译

export ARCH=arm

export CROSS_COMPILE=arm-linux-gnueabi-

./configure --prefix=/usr     \

--sysconfdir=/etc \

--disable-static  &&

make

然后执行sudo make install，libnl.so会被安装至/usr/local/lib/目录下，相应的头文件也会被copy到/usr/local/include/netlink下。

如果报出编译错误：“../include/netlink_local.h:218:error 'ULONG_MAX' undeclared"，我们在对应文件添加一个头文件 #include即可解决问题；

编译openssl

进入openssl目录， ./config shared # 一定要加shared, 否则编译出来的是静态库。执行make进行编译，完成后执行make install，编译好的openssl库和头文件等被安装在目录/usr/local/ssl下

export ARCH=arm

export CROSS_COMPILE=arm-linux-gnueabi-

./config --prefix=/usr         \

--openssldir=/etc/ssl \

--libdir=lib          \

shared                \

zlib-dynamic &&

make

If you want to disable installing the static libraries, use this sed:

sed -i 's# libcrypto.a##;s# libssl.a##' Makefile

Now, as the root user:

make MANDIR=/usr/share/man MANSUFFIX=ssl install &&

install -dv -m755 /usr/share/doc/openssl-1.0.2e  &&

cp -vfr doc/*     /usr/share/doc/openssl-1.0.2e

编译wpa_supplicant

添加修改配置文件

进入wpa_supplicant/wpa_supplicant目录，执行cp defconfig .config 拷贝生成编译配置，然后修改配置文件 .config，

#如果选择的不是libnl的1.0版本，需要根据libnl的版本打开下面的选项

CONFIG_LIBNL32=y

CONFIG_LIBNL20=y 选择libnl的版本

#添加openssl和libnl的头文件和库文件目录，更新编译链接环境变量

CFLAGS += -I/usr/local/ssl/include

CFLAGS += -I/usr/local/include/ libnl3

CFLAGS += -I/usr/local/include/netlink

LIBS += -L/usr/local/ssl/lib

LIBS += -L/usr/local/lib

LIBS_p += -L/usr/local/ssl/lib # 不加此行，编wpa_passphrase出错。

cp defconfig .config

make CC=arm-linux-gnueabi-gcc

make install DESTDIR=/home/export/rootfs

执行make进行编译

成功后生成三个目标文件wpa_supplicant, wpa_cli, wpa_passphrase，至此编译完成。

运行wpa_supplicant

需要保证libssl库在我们的搜索路径里，否则不做处理，会出现找不到libnl, ssl 和crypto库的错误。

./wpa_supplicant

./wpa_supplicant: error while loading shared libraries: libssl.so.1.1.0: cannot open shared object file: No such file or directory

将/usr/local/ssl/lib下的libssl.so.x.x.x 和 libcrypto.so.xxx 拷贝到/lib目录下即可，或者：export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/ssl/lib，或者在/etc/ld.so.conf 文件中添加库的搜索路径。(或者在/etc/ld.so.conf.d 下新建一个.conf文件，将搜索路径一行一个加入).

cp /usr/arm-linux-gnueabi/lib/libnl.so.1.1.4 /home/export/rootfs/lib/

cp /usr/arm-linux-gnueabi/lib/libcrypto.so.1.0.0 /home/export/rootfs/lib/

cp /usr/arm-linux-gnueabi/lib/libssl.so.1.0.0 /home/export/rootfs/lib/

配置wpa_supplicant

wpa_supplicant runs as a daemon and requires a configuration file. Create a file called /etc/wpa_supplicant.conf with the following contents:

network={

ssid="MySSID"

key_mgmt=WPA-PSK

proto=RSN

pairwise=CCMP TKIP

psk="MyPassPhrase"

}

The above file works with both WPA (TKIP) and WPA2 (CCMP/AES). Please insert your access point name at MySSID and your pass phrase at MyPassPhase.

Once configured, wpa_supplicant can be started using:

wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant.conf

编译错误处理

Error#1

#######################################################################

CC  ../src/drivers/driver_wired.c

../src/drivers/driver_nl80211.c:25:31: fatal error: netlink/genl/genl.h: No such file or directory

compilation terminated.

make: *** [../src/drivers/driver_nl80211.o] Error 1

#######################################################################

Solution #1

sudo apt-get -y install libssl-dev libnl-3-dev

echo CFLAGS +=-I/usr/include/libnl3/ >> .config

make

Error#2

../src/drivers/driver_nl80211.c:95:9: warning: passing argument 1 of ‘genl_ctrl_alloc_cache’ from incompatible pointer type [enabled by default]

/usr/include/libnl3/netlink/genl/ctrl.h:25:14: note: expected ‘struct nl_sock *’ but argument is of type ‘struct nl_handle *’

../src/drivers/driver_nl80211.c:95:9: error: too few arguments to function ‘genl_ctrl_alloc_cache’

/usr/include/libnl3/netlink/genl/ctrl.h:25:14: note: declared here

Solution #2

sudo apt-get install libnl-genl-3-dev

echo CONFIG_LIBNL32=y >> .config

make

Usage

usage:

wpa_supplicant [-BddhKLqqtvW] [-P] [-g] \

[-G] \

-i-c [-C] [-D] [-p] \

[-b] [-e] \

[-o] [-O] \

[-N -i -c [-C] [-D] \

[-p] [-b] [-I] …]

drivers:

nl80211 = Linux nl80211/cfg80211

wext = Linux wireless extensions (generic)

wired = Wired Ethernet driver

options:

-b = optional bridge interface name

-B = run daemon in the background

-c = Configuration file

-C = ctrl_interface parameter (only used if -c is not)

-i = interface name

-I = additional configuration file

-d = increase debugging verbosity (-dd even more)

-D = driver name (can be multiple drivers: nl80211,wext)

-e = entropy file

-g = global ctrl_interface

-G = global ctrl_interface group

-K = include keys (passwords, etc.) in debug output

-t = include timestamp in debug messages

-h = show this help text

-L = show license (BSD)

-o = override driver parameter for new interfaces

-O = override ctrl_interface parameter for new interfaces

-p = driver parameters

-P = PID file

-q = decrease debugging verbosity (-qq even less)

-v = show version

-W = wait for a control interface monitor before starting

-N = start describing new interface

example:

wpa_supplicant -Dnl80211 -iwlan0 -c/etc/wpa_supplicant.conf

wpa_cli [-pctrl sockets>] [-i] [-hvB] [-a] \

[-P] [-g] [-G]  [command..]

-h = help (show this usage text)

-v = shown version information

-a = run in daemon mode executing the action file based on events from

wpa_supplicant

-B = run a daemon in the background

default path: /var/run/wpa_supplicant

default interface: first interface found in socket path

commands:

status [verbose] = get current WPA/EAPOL/EAP status

ifname = get current interface name

ping = pings wpa_supplicant

relog = re-open log-file (allow rolling logs)

note = add a note to wpa_supplicant debug log

mib = get MIB variables (dot1x, dot11)

help [command] = show usage help

interface [ifname] = show interfaces/select interface

level = change debug level

license = show full wpa_cli license

quit = exit wpa_cli

set = set variables (shows list of variables when run without arguments)

get = get information

logon = IEEE 802.1X EAPOL state machine logon

logoff = IEEE 802.1X EAPOL state machine logoff

pmksa = show PMKSA cache

reassociate = force reassociation

preauthenticate = force preauthentication

identity = configure identity for an SSID

password = configure password for an SSID

new_password = change password for an SSID

pin = configure pin for an SSID

otp = configure one-time-password for an SSID

passphrase = configure private key passphrase

for an SSID

sim = report SIM operation result

bssid = set preferred BSSID for an SSID

blacklist = add a BSSID to the blacklist

blacklist clear = clear the blacklist

blacklist = display the blacklist

log_level [] = update the log level/timestamp

log_level = display the current log level and log options

list_networks = list configured networks

select_network = select a network (disable others)

enable_network = enable a network

disable_network = disable a network

add_network = add a network

remove_network = remove a network

set_network = set network variables (shows

list of variables when run without arguments)

get_network = get network variables

list_creds = list configured credentials

add_cred = add a credential

remove_cred = remove a credential

set_cred = set credential variables

save_config = save the current configuration

disconnect = disconnect and wait for reassociate/reconnect command before

connecting

reconnect = like reassociate, but only takes effect if already disconnected

scan = request new BSS scan

scan_results = get latest scan results

bss < | > = get detailed scan result info

get_capability = get capabilies

reconfigure = force wpa_supplicant to re-read its configuration file

terminate = terminate wpa_supplicant

interface_add = adds new interface, all parameters but are optional

interface_remove = removes the interface

interface_list = list available interfaces

ap_scan = set ap_scan parameter

scan_interval = set scan_interval parameter (in seconds)

bss_expire_age = set BSS expiration age parameter

bss_expire_count = set BSS expiration scan count parameter

bss_flush = set BSS flush age (0 by default)

stkstart = request STK negotiation with

ft_ds = request over-the-DS FT with wps_pbc [BSSID] = start Wi-Fi Protected Setup: Push Button Configuration

wps_pin [PIN] = start WPS PIN method (returns PIN, if not hardcoded)

wps_check_pin = verify PIN checksum

wps_cancel Cancels the pending WPS operation

wps_reg = start WPS Registrar to configure an AP

wps_ap_pin [params..] = enable/disable AP PIN

wps_er_start [IP address] = start Wi-Fi Protected Setup External Registrar

wps_er_stop = stop Wi-Fi Protected Setup External Registrar

wps_er_pin = add an Enrollee PIN to External Registrar

wps_er_pbc = accept an Enrollee PBC using External Registrar

wps_er_learn = learn AP configuration

wps_er_set_config = set AP configuration for enrolling

wps_er_config = configure AP

ibss_rsn = request RSN authentication with in IBSS

sta = get information about an associated station (AP)

all_sta = get information about all associated stations (AP)

deauthenticate = deauthenticate a station

disassociate = disassociate a station

chan_switch [sec_channel_offset=] [center_freq1=] [center_freq2=] [bandwidth=] [blocktx] [ht|vht] = CSA parameters

suspend = notification of suspend/hibernate

resume = notification of resume/thaw

drop_sa = drop SA without deauth/disassoc (test command)

roam = roam to the specified BSS

p2p_find [timeout] [type=*] = find P2P Devices for up-to timeout seconds

p2p_stop_find = stop P2P Devices search

p2p_connect [ht40] = connect to a P2P Device

p2p_listen [timeout] = listen for P2P Devices for up-to timeout seconds

p2p_group_remove = remove P2P group interface (terminate group if GO)

p2p_group_add [ht40] = add a new P2P group (local end as GO)

p2p_prov_disc = request provisioning discovery

p2p_get_passphrase = get the passphrase for a group (GO only)

p2p_serv_disc_req = schedule service discovery request

p2p_serv_disc_cancel_req = cancel pending service discovery request

p2p_serv_disc_resp = service discovery response

p2p_service_update = indicate change in local services

p2p_serv_disc_external = set external processing of service discovery

p2p_service_flush = remove all stored service entries

p2p_service_add = add a local service

p2p_service_del [|service] = remove a local service

p2p_reject = reject connection attempts from a specific peer

p2p_invite [peer=addr] = invite peer

p2p_peers [discovered] = list known (optionally, only fully discovered) P2P peers

p2p_peer = show information about known P2P peer

p2p_set = set a P2P parameter

p2p_flush = flush P2P state

p2p_cancel = cancel P2P group formation

p2p_unauthorize

= unauthorize a peer

p2p_presence_req [] [] = request GO presence

p2p_ext_listen [] = set extended listen timing

p2p_remove_client = remove a peer from all groups

sta_autoconnect <0/1> = disable/enable automatic reconnection

tdls_discover = request TDLS discovery with

tdls_setup = request TDLS setup with

tdls_teardown = tear down TDLS with

signal_poll = get signal parameters

pktcnt_poll = get TX/RX packet counters

reauthenticate = trigger IEEE 802.1X/EAPOL reauthentication

raw = Sent unprocessed command

flush = flush wpa_supplicant state

radio_work = radio_work Configuration

Set wpa_supplicant.conf to the following:

You have to change the values according to the response of

# wpa_passphrase .

For WPA-PSK

ctrl_interface=/var/run/wpa_supplicant

ctrl_interface_group=0

eapol_version=1

# ap_scan=2 was the one for me you may try 0 or 1 indstead of 2

ap_scan=2

fast_reauth=1

network={

ssid="my_network"

proto=WPA

key_mgmt=WPA-PSK

pairwise=TKIP

group=TKIP

psk="secret_password"

}

For WPA2-Personal

ctrl_interface=/var/run/wpa_supplicant

ctrl_interface_group=0

ap_scan=1

network={

ssid="my_network"

proto=RSN

key_mgmt=WPA-PSK

pairwise=CCMP TKIP

group=CCMP TKIP

psk="secret_password"

}

Bringing up the network card manually

Bring up the network interface with

# ifconfig ath0 up

.

NOTE!

At the moment there is a problem within the madwifi driver or wpa_supplicant passing dhcp. That??s why I use a fixed IP.

There are two patches one for wpa_supllicant (http://hostap.epitest.fi/bugz/show_bug.cgi?id=63) and one for madwifi

(http://article.gmane.org/gmane.linux.drivers.madwifi.devel/1275). Each one is supposed to work.

Change the routes and add the default gateway.

Bringing up the device at boottime (for Gentoo users)

Make a symbolic link# cd /etc/init.d/

# ln -s net.lo net.ath0

Copy wpa_supplicant.conf to /etc/conf.d/wpa_supplicant.

Edit /etc/conf.d/net

#

#net

#

modules=( "wpa_supplicant" )

wpa_supplicant_ath0="-Dmadwifi"modules=( "wpa_supplicant" )

wpa_timeout_ath0=60

config_ath0=("netmask 255.255.255.0")

routes_ath0=("default gw ")

Add net.ath0 to the default runlevel by executing

# rc-update add net.ath0 default

Make sure all needed modules are in /etc/modules.autoload/2.x

iw的编译和配置运行

iw is a new nl80211 (802.11 netlink interface) based CLI configuration utility for wireless devices.

Netlink Protocol Library Suite

Download, cross compile and install the Netlink Protocol libraries:

wget http://www.infradead.org/~tgr/libnl/files/libnl-3.2.24.tar.gz

tar -xzf libnl-3.2.24.tar.gz

cd libnl-3.2.24

./configure --host=arm-linux-gnueabi --prefix=/usr/arm-linux-gnueabi

make

make install

cd include

make install

iw

With the Netlink Protocol Library Suite prerequisite installed, download and build the iw nl80211 based CLI configuration utility:

wget https://www.kernel.org/pub/software/network/iw/iw-3.15.tar.gz

tar -xzf iw-3.15.tar.gz

cd iw-3.15/

export PKG_CONFIG_PATH=/usr/arm-linux-gnueabi/lib/pkgconfig

export CC=arm-linux-gnueabi-gcc

make

Manually install iw and required libraries on your target root-fs:

cp iw /home/export/rootfs/sbin/

cp /usr/arm-linux-gnueabi/lib/libnl-genl-3.so.200 /home/export/rootfs/lib/

cp /usr/arm-linux-gnueabi/lib/libnl-3.so.200 /home/export/rootfs/lib/

And update the dynamic linker run-time bindings on your target:

ldconfig -v

hostapd

hostapd is an 802.11 Access Point and IEEE 802.1X/WPA/WPA2/EAP/RADIUS Authenticator daemon.

Download, extract and build hostapd:

wget http://hostap.epitest.fi/releases/hostapd-2.2.tar.gz

tar -xzf hostapd-2.2.tar.gz

cd hostapd-2.2/hostapd

cp defconfig .config

make CC=arm-linux-gnueabi-gcc

make install DESTDIR=/home/export/rootfs

rfkill is a userspace tool to query the state of the rfkill switches.

Download, extract and build rfkill:

tar -xzf rfkill-0.5.tar.gz

cd rfkill-0.5/

make CC=arm-linux-gnueabi-gcc