cxcc BLOG

 cxcc BLOG

wifi工具的使用

一、工具移植

一般Linux中进行wifi扫描、连接需要以下工具wpa_supplicant、Wireless Tools、hostapd。具体的移植参考《工具移植.md》

Wireless Tools：进行wifi网卡的基本配置，网络扫描

wpa_supplicant：进行网络连接

hostapd：创建wifi热点

二、工具使用

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# 在执行命令前需要先启动网卡
ifconfig wlan0 up

  1. 扫描附近的网络

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    iwlist wlan0 scanning

  2. 连接指定的网络

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    # 创建配置文件
    vi /etc/wpa_supplicant/wpa_supplicant.conf
    network={
        ssid="YourWiFiNetwork"
        psk="YourWiFiPassword"
    }
    # 连接wifi，在后台保持连接
    sudo wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf

  3. 创建wifi热点

    • 创建配置文件/etc/hostapd.conf

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      interface=wlan1
      ctrl_interface=/var/run/hostapd
      ssid=Ebaina-test
      channel=6
      driver=nl80211
      wpa=2
      wpa_passphrase=12345678
      wpa_key_mgmt=WPA-PSK
      beacon_int=100
      hw_mode=g
      ieee80211n=1
      wme_enabled=1
      ht_capab=[SHORT-GI-20][SHORT-GI-40][HT40+]
      wpa_pairwise=CCMP
      #rsn_pairwise=CCMP
      max_num_sta=8
      wpa_group_rekey=86400
      #ignore_broadcast_ssid=0

    • 启动热点，后台执行

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      hostapd ./hostapd.config -ddd &

  4. 获取动态IP

    • 创建默认脚本/usr/share/udhcpc/default.script/default.script

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      #!/bin/sh
      # udhcpc script edited by Tim Riker <Tim@Rikers.org>

      RESOLV_CONF="/etc/resolv.conf"

      [ -n "$1" ] || { echo "Error: should be called from udhcpc"; exit 1; }

      NETMASK=""
      if command -v ip >/dev/null; then
      	[ -n "$subnet" ] && NETMASK="/$subnet"
      else
      	[ -n "$subnet" ] && NETMASK="netmask $subnet"
      fi
      BROADCAST="broadcast +"
      [ -n "$broadcast" ] && BROADCAST="broadcast $broadcast"

      case "$1" in
      	deconfig)
      		echo "Setting IP address 0.0.0.0 on $interface"
      		if command -v ip >/dev/null; then
      			ip addr flush dev $interface
      		else
      			ifconfig $interface 0.0.0.0
      		fi
      		;;

      	renew|bound)
      		echo "Setting IP address $ip on $interface"
      		if command -v ip >/dev/null; then
      			ip addr add $ip$NETMASK $BROADCAST dev $interface
      		else
      			ifconfig $interface $ip $NETMASK $BROADCAST
      		fi

      		if [ -n "$router" ] ; then
      			echo "Deleting routers"
      			while route del default gw 0.0.0.0 dev $interface ; do
      				:
      			done

      			metric=0
      			for i in $router ; do
      				echo "Adding router $i"
      				if [ "$subnet" = "255.255.255.255" ]; then
      	# special case for /32 subnets:
      	# /32 instructs kernel to always use routing for all outgoing packets
      	# (they can never be sent to local subnet - there is no local subnet for /32).
      	# Used in datacenters, avoids the need for private ip-addresses between two hops.
      					ip route add $i dev $interface
      				fi
      				route add default gw $i dev $interface metric $((metric++))
      			done
      		fi

      		echo "Recreating $RESOLV_CONF"
      		# If the file is a symlink somewhere (like /etc/resolv.conf
      		# pointing to /run/resolv.conf), make sure things work.
      		if test -L "$RESOLV_CONF"; then
      			# If it's a dangling symlink, try to create the target.
      			test -e "$RESOLV_CONF" || touch "$RESOLV_CONF"
      		fi
      		realconf=$(readlink -f "$RESOLV_CONF" 2>/dev/null || echo "$RESOLV_CONF")
      		tmpfile="$realconf-$$"
      		> "$tmpfile"
      		[ -n "$domain" ] && echo "search $domain" >> "$tmpfile"
      		for i in $dns ; do
      			echo " Adding DNS server $i"
      			echo "nameserver $i" >> "$tmpfile"
      		done
      		mv "$tmpfile" "$realconf"
      		;;
      esac

      exit 0

    • 获取动态IP

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      udhcpc -i wlan0

  5. 允许其它设备从热点获取动态IP（开启DHCP服务）

    • 创建配置文件/etc/udhcpd.conf

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      start           192.168.43.50   
      end             192.168.43.100  
      interface       wlan1          

      #Examles
      opt     dns     192.168.43.2 192.168.43.10
      option  subnet   255.255.255.0
      opt     router   192.168.43.1
      opt     wins     192.168.43.10
      option  dns      129.219.13.81  
      option  domain   local
      option  lease   864000

    • 启动DHCP服务

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      udhcpd -S /etc/udhcpd.conf
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