wpa_supplicant管理无线wifi网络

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	本帖最后由 非也 于 2013-3-27 18:17 编辑     为了感谢大家一直以来对天嵌科技的支持和鼓励，公司决定陆续放出Linux实用工具教程，希望大家一如既往的支持天嵌，天嵌的发展离不开广大的朋友！    “授人以鱼不如授人以渔”，天嵌科技本着负责任的态度教大家如何使用和开发，助您翱翔于嵌入式的天空！     本次介绍的是使用wpa_supplicant管理连接无线wifi网络，有不对之处希望大家多多指正，谢谢。           wpa移植及内核配置。     1、保证wifi模块处于准备状态。      使用iwlist能搜索出ap，表示模块已经就绪。 [root@EmbedSky /]# ifconfig wlan0 down [root@EmbedSky /]# ifconfig wlan0 up MacValue1=2 MacValue2=0 0x1300 = 00064300 [root@EmbedSky /]# iwlist wlan0 scanning wlan0     Scan completed :           Cell 01 - Address: 00:23:89:82:88:A0                     Protocol:802.11b/g                     ESSID:"ChinaNet"                     Mode:Managed                     Frequency:2.412 GHz (Channel 1)                     Quality=78/100  Signal level=-59 dBm  Noise level=-92 dBm                     Encryption key:off                     Bit Rates:54 Mb/s           Cell 02 - Address: 00:23:89:82:88:A1                     Protocol:802.11b/g                     ESSID:"hsfz"                     Mode:Managed                     Frequency:2.412 GHz (Channel 1)                     Quality=2/100  Signal level=-89 dBm  Noise level=-84 dBm                     Encryption key:off                     Bit Rates:54 Mb/s 复制代码    2、根据实际wifi参数修改/etc/wpa_supplicant.conf配置文件                                                               注意ctrl_interface，ssid，key_mgmt，proto，psk，要根据wifi实际情况修改。 fast_reauth=1 ctrl_interface=wlan0 update_config=1 ap_scan=1 network={         ssid="EmbedSky_test"         scan_ssid=1         key_mgmt=WPA-PSK         proto=WPA         pairwise=TKIP         group=TKIP        psk="1234567890" } 复制代码     3、调用wpa_supplicant连接wifi     wext为wifi模块使用的驱动协议，wlan0是wifi模块的设备名 wpa_supplicant  -Dwext -iwlan0 -c/etc/wpa_supplicant.conf  -dd& 复制代码         以下是wpa_supplicant连接时的打印信息（部分）：        RX EAPOL from 00:27:19:64:f8:a8 RX EAPOL - hexdump(len=99): 01 03 00 5f fe 00 89 00 20 00 00 00 00 00 00 00 01 eb 6b f1 83 4a cb a4 28 65 85 ee 0 Setting authentication timeout: 10 sec 0 usec IEEE 802.1X RX: version=1 type=3 length=95 WPA: Installing GTK to the driver (keyidx=1 tx=0 len=32). WPA: RSC - hexdump(len=6): 00 00 00 00 00 00 wpa_driver_wext_set_key: alg=2 key_idx=1 set_tx=0 seq_len=6 key_len=32 WPA: Sending EAPOL-Key 2/2 WPA: TX EAPOL-Key - hexdump(len=99): 01 03 00 5f fe 03 11 00 20 00 00 00 00 00 00 00 03 00 00 00 00 00 00 00 00 0 WPA: Key negotiation completed with 00:27:19:64:f8:a8 [PTK=TKIP GTK=TKIP] Cancelling authentication timeout Removed BSSID 00:27:19:64:f8:a8 from blacklist State: GROUP_HANDSHAKE -> COMPLETED CTRL-EVENT-CONNECTED - Connection to 00:27:19:64:f8:a8 completed (auth) [id=0 id_str=] wpa_driver_wext_set_operstate: operstate 0->1 (UP) WEXT: Operstate: linkmode=-1, operstate=6 EAPOL: External notification - portValid=1 EAPOL: External notification - EAP success=1 EAPOL: SUPP_PAE entering state AUTHENTICATING EAPOL: SUPP_BE entering state SUCCESS EAP: EAP entering state DISABLED EAPOL: SUPP_PAE entering state AUTHENTICATED EAPOL: SUPP_BE entering state IDLE EAPOL authentication completed successfully RTM_NEWLINK: operstate=1 ifi_flags=0x11043 ([UP][RUNNING][LOWER_UP]) RTM_NEWLINK, IFLA_IFNAME: Interface 'wlan0' added EAPOL: startWhen --> 0 EAPOL: disable timer tick RSN: processing PMKSA candidate list RSN: not in suitable state for new pre-authentication 复制代码     看到CTRL-EVENT-CONNECTED,就表示连接成功了。           4、给wifi模块动态分配IP [root@EmbedSky sky]# ping ping: bad address '' [root@EmbedSky sky]# ping ping: bad address '' [root@EmbedSky sky]# udhcpc -b -i wlan0 udhcpc (v1.16.0) started Ignore event for foreign ifindex 2 Sending discover... Sending select for 192.168.1.229... Lease of 192.168.1.229 obtained, lease time 7200 Ignore event for foreign ifindex 2 deleting routers route: SIOCDELRT: No such process adding dns 192.168.1.2 adding dns 0.0.0.0 [root@EmbedSky sky]# ping PING (61.135.169.105): 56 data bytes 64 bytes from 61.135.169.105: seq=0 ttl=54 time=306.288 ms ^C --- ping statistics --- 2 packets transmitted, 1 packets received, 50% packet loss round-trip min/avg/max = 306.288/306.288/306.288 ms 复制代码     5、给wifi模块分配静态IP                      首先要先设置DNS，/etc/resolv.conf文件，请根据实际情况修改 nameserver 202.96.128.86 nameserver 202.96.134.133 复制代码     关闭eth0，否则会默认使用eth0来连接网络。添加路由，否则无法连通网络。 [root@EmbedSky /]# ifconfig wlan0 192.168.1.22 [root@EmbedSky /]# ifconfig eth0 down Ignore event for foreign ifindex 2 [root@EmbedSky /]# ifconfig eth0 down [root@EmbedSky /]# route add default gw 192.168.1.2 [root@EmbedSky /]# ping PING (61.135.169.125): 56 data bytes 64 bytes from 61.135.169.125: seq=0 ttl=54 time=216.279 ms 64 bytes from 61.135.169.125: seq=1 ttl=54 time=214.120 ms ^C --- ping statistics --- 9 packets transmitted, 5 packets received, 44% packet loss round-trip min/avg/max = 212.083/222.935/244.256 ms [root@EmbedSky /]# 复制代码   FAQ：     1、无法连接ap     内核中Networking support-> Networking options -> Packet socket，添加支持。要确保wifi模块处理就绪状态，使用iwlist wlan0 scanning命令判断。     2、连上后无法动态分配IP     确保内核已经选上dhcp支持。     3、IP分配成功后无法访问外网     请设置dns和路由。