Android wpa_supplcant Startup--Global initialization

1. Wpa_supplicant Introduction

Wpa_supplicant is used to support various encryption methods in wireless, including WEP, WPA/WPA2, and WAPI (China-specific), EAP (8021x). wpa_s communicates with the upper layer (framework) and the underlying (driver) through the socket, receives commands and passes the current state up, sends commands down to the driver and receives the various events that drive uploads, and strictly speaking, there is a cfg80211 in wap_s and driver. Cfg80211 can be understood as a Linux defined 80211 management control layer framework, such as scanning, connecting these common processes, each vendor according to the framework provided by the cfg80211 to write their own driver, to achieve specific frame sending and receiving. wpa_s How to handle the data in each socket see the Eloop Sun section.
is a picture on the Web page (http://zwz94.blog.163.com/blog/static/3206039520120149580531/) that can clearly see the location of the wpa_s in the entire WiFi architecture

1. Wpa_supplicant Start-up

On Android phones, the wpa_supplicant boot is controlled by the framework, and Frameowork sets the property to start the service written in the init RC file, while generating two sockets, one to Wpa_ s send command, a receive wpa_s upload event

Service P2p_supplicant/system/bin/wpa_supplicant\    -ip2p0 -dnl80211 - C/Data/misc/wifi/p2p_supplicant.Conf\    - I./system/etc/wifi/p2p_supplicant_overlay.Conf- N \    -iwlan0 -dnl80211 - C/Data/misc/wifi/wpa_supplicant.Conf\    - I./system/etc/wifi/wpa_supplicant_overlay.Conf\    - o/Data/misc/wifi/sockets-puse_p2p_group_interface=1 -DD \    - e/Data/misc/wifi/entropy.Bin- G@android: Wpa_wlan0 class main socket wpa_wlan0 Dgram660WiFi WiFi disabled oneshot

where socket wpa_wlan0 Dgram 660 WiFi WiFi created a socket,wpa_s using the socket to receive the framework commands and to pass the event up. The framework will also call to connect to the socket, which will later

1. Wpa_supplicant Startup Parameters

wpa_s allow many parameters to be passed in, parameters are case-sensitive
The parameters are in a total of 3 types,

• 3.1 Without subsequent content,

Have –BDHKLQSTUVW
-H: Help file
-L: Output license
-Q: Raise the wpa_s debug level (output log reduction), in contrast to-D
-V: Output wpa_s version number
-W: Wait until control Interface monitor runs again
-N: When you need to set up two network interface, you need to insert –N in the middle of two port parameters, for example, a network port is p2p0, need to insert-N, and then add another wlan0

• 3.2 With subsequent content, control wpa_s operation parameters, can also be called global parameters

struct Wpa_params is used in calling Wpa_supplicant_init () initialization wpa_s

structWpa_params {//-b: Running in the background as a daemon    intDaemonize;//-w: Wait until control Interface monitor runs again    intWait_for_monitor;//-p:pid_file-path to a PID (process ID) file    Char*pid_file;//-d: The level of output log,-D is the default level, the-DD level is reduced by one level (output log will increase by one level), and so on, the code is set to Params.wpa_debug_level    intWpa_debug_level;//-k: Print key in log    intWpa_debug_show_keys;//-t: Increase timestamp in debug information    intWpa_debug_timestamp;//ctrl_interface-global ctrl_iface Path/parameter    //-g:global ctrl_interface (string is @android+sock_name, Sock_name is by init.rc)    Char*ctrl_interface;//ctrl_interface_group-global ctrl_iface Group    //-g:global ctrl_interface Group    Char*ctrl_interface_group;//-u: Supports Dbus control Interface    intDbus_ctrl_interface;//-f: Output log to File    Const Char*wpa_debug_file_path;//-s: Output log to Syslog, default output to stdout    intWpa_debug_syslog;//-t:log add Linux trace    intwpa_debug_tracing;//-o: Setting up a directory for the Linux network Port    Char*override_driver;//-o: Setting the directory for wpa_s control sockets    Char*override_ctrl_interface;//-e:entropy_file-optional Entropy File    Char*entropy_file;};

• 3.3 With subsequent content, interface-related, also called interface parameters

stored in struct struct wpa_interface, running Wpa_supplicant_add_iface () needs to pass in the struct

structWpa_interface {//-c:conf configuration file, which defines some parameters and some network nodes, typically wpa_supplicant.conf    Const Char*confname;Supplemental options for the//-i:conf configuration file, typically wpa_supplicant_overlay.conf/    Const Char*confanother;//-m:p2p Network port configuration file    Const Char*conf_p2p_dev;//-c: Parameters of the control port socket    //function equivalent to conf file    Const Char*ctrl_interface;type of//-d:driver, you can set multiple, such as Nl80211,wext    Const Char*driver;//driver_param-driver Interface Parameters    Const Char*driver_param;//-i:linux, you can define multiple, such as Wlan0    Const Char*ifname;//-b: Bridging the interface    Const Char*bridge_ifname;//p2p_mgmt-interface used for peer management (peer Device Operations)    intP2P_MGMT;};

1. wpa_s Global Initialization
   The main include EAP various methods of registration, Eloop (wpa_s run the main) parameters, with the framework of communication socket initialization

struct Wpa_global*Wpa_supplicant_init (struct wpa_params*params){//Global information, the contents of the params will be copied into the structurestruct Wpa_global*Global;//Initialize the EAP method with a corresponding method for each EAP modeRet=Eap_register_methods ();//Copy the information in the params to global    Global =Os_zalloc (sizeof (*Global));//Initialize struct eloop_data, the struct is a global variable    if(Eloop_init ()) Random_init (params -Entropy_file);//Connect with Fwks communication socket (defined in init.rc), and register the function that receives CMD    Global -Ctrl_iface=Wpa_supplicant_global_ctrl_iface_init (Global); {//Initialize control socketWpas_global_ctrl_iface_open_sock (Global, Priv)< 0)        {//Get the name of the socket-G pass in, corresponding to the init.rcOS_STRNCMP (CTRL,"@android:",9)== 0) {Priv -Sock=Android_get_control_socket (Ctrl+ 9);//Register function wpa_supplicant_global_ctrl_iface_process to receive socket data, distribute and process incoming commandsEloop_register_read_sock (priv -Sock, Wpa_supplicant_global_ctrl_iface_receive,Global, PRIV);//Register a function to send event to Fwks wpa_supplicant_ctrl_iface_sendWPA_MSG_REGISTER_CB (WPA_SUPPLICANT_CTRL_IFACE_MSG_CB); }    }return Global;}

is a simple global initialization process

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Android wpa_supplcant Startup--Global initialization