WifiCommand流程 wpa_supplicant启动流程 Wifiservice启动流程（转）

1. 信号强度算法

    WifiManager.java

 

1. /** Anything worse than or equal to this will show 0 bars. */  
2. private static final int MIN_RSSI = -100;  
3.   
4. /** Anything better than or equal to this will show the max bars. */  
5. private static final int MAX_RSSI = -55;  
6.   
7. /** 
8.  * Calculates the level of the signal. This should be used any time a signal 
9.  * is being shown. 
10.  * 
11.  * @param rssi The power of the signal measured in RSSI. 
12.  * @param numLevels The number of levels to consider in the calculated 
13.  *            level. 
14.  * @return A level of the signal, given in the range of 0 to numLevels-1 
15.  *         (both inclusive). 
16.  */  
17. public static int calculateSignalLevel(int rssi, int numLevels) {  
18.     /* in general, numLevels is 4  */  
19.     if (rssi <= MIN_RSSI) {  
20.         return 0;  
21.     } else if (rssi >= MAX_RSSI) {  
22.         return numLevels - 1;  
23.     } else {  
24.         float inputRange = (MAX_RSSI - MIN_RSSI);  
25.         float outputRange = (numLevels - 1);  
26.           
27.         return (int)((float)(rssi - MIN_RSSI) * outputRange / inputRange);  
28.     }  
29. }  

    /** Anything worse than or equal to this will show 0 bars. */
    private static final int MIN_RSSI = -100;

    /** Anything better than or equal to this will show the max bars. */
    private static final int MAX_RSSI = -55;

    /**
     * Calculates the level of the signal. This should be used any time a signal
     * is being shown.
     *
     * @param rssi The power of the signal measured in RSSI.
     * @param numLevels The number of levels to consider in the calculated
     *            level.
     * @return A level of the signal, given in the range of 0 to numLevels-1
     *         (both inclusive).
     */
    public static int calculateSignalLevel(int rssi, int numLevels) {
        /* in general, numLevels is 4  */
        if (rssi <= MIN_RSSI) {
            return 0;
        } else if (rssi >= MAX_RSSI) {
            return numLevels - 1;
        } else {
            float inputRange = (MAX_RSSI - MIN_RSSI);
            float outputRange = (numLevels - 1);
            
            return (int)((float)(rssi - MIN_RSSI) * outputRange / inputRange);
        }
    }

 

2. WiFi Command流程

 

3. wpa_supplicant启动流程

4. WifiService启动流程

5. SIGNAL_POLL调用流程

 

1. eloop_run->..  
2. wpa_supplicant_ctrl_iface_receive-> //接收并处理来自framework的command   
3. wpa_supplicant_ctrl_iface_process-> (SIGNAL_POLL)  
4. wpa_supplicant_signal_poll->  
5. wpa_drv_signal_poll  (struct wpa_supplicant *wpa_s,struct wpa_signal_info *si)->  
6. wpa_driver_signal_poll  (void *priv, struct wpa_signal_info *si)->  
7.     wpa_driver_wext_driver_cmd(priv, RSSI_CMD, buf, sizeof(buf))或  //driver_cmd_wext.c   
8.     wpa_driver_wext_driver_cmd(priv, LINKSPEED_CMD, buf, sizeof(buf))->  
9.         
10.       struct iwreq iwr;  
11.       iwr.u.data.pointer = buf;  
12.       iwr.u.data.length = buf_len;  
13.       ioctl(drv->ioctl_sock, SIOCSIWPRIV, &iwr);  
14.       在Kernel中对应函数：  
15.       cfg80211_wext_setpriv (wext-compat.c)  
16.       RSSI_CMD:  
17.       cfg80211_wireless_stats (获取当前已连接AP的信号强度等信息)  
18.   
19.      对于上面的LINKSPEED_CMD,如果ioctl不成功，则调用ioctl(drv->ioctl_sock, SIOCGIWRATE, &wrq)  
20.      在Kernel中对应函数：  
21.      cfg80211_wext_giwrate (获取当前已连接AP的发送速度)  
22.   
23.      //每个AP对应的信息        
24.      struct station_info {  
25.     u32 filled;  
26.     u32 connected_time;  
27.     u32 inactive_time;  
28.     u32 rx_bytes;  
29.     u32 tx_bytes;  
30.     u16 llid;  
31.     u16 plid;  
32.     u8 plink_state;  
33.     s8 signal;  //信号强度   
34.     s8 signal_avg;  
35.     struct rate_info txrate;  //发送速度   
36.     struct rate_info rxrate;  
37.     u32 rx_packets;  
38.     u32 tx_packets;  
39.     u32 tx_retries;  
40.     u32 tx_failed;  
41.     u32 rx_dropped_misc;  
42.     struct sta_bss_parameters bss_param;  
43.   
44.     int generation;  
45.     };  

eloop_run->..
wpa_supplicant_ctrl_iface_receive-> //接收并处理来自framework的command
wpa_supplicant_ctrl_iface_process-> (SIGNAL_POLL)
wpa_supplicant_signal_poll->
wpa_drv_signal_poll  (struct wpa_supplicant *wpa_s,struct wpa_signal_info *si)->
wpa_driver_signal_poll  (void *priv, struct wpa_signal_info *si)->
    wpa_driver_wext_driver_cmd(priv, RSSI_CMD, buf, sizeof(buf))或  //driver_cmd_wext.c
    wpa_driver_wext_driver_cmd(priv, LINKSPEED_CMD, buf, sizeof(buf))->
      
      struct iwreq iwr;
      iwr.u.data.pointer = buf;
      iwr.u.data.length = buf_len;
      ioctl(drv->ioctl_sock, SIOCSIWPRIV, &iwr);
      在Kernel中对应函数：
      cfg80211_wext_setpriv (wext-compat.c)
      RSSI_CMD:
      cfg80211_wireless_stats (获取当前已连接AP的信号强度等信息)

     对于上面的LINKSPEED_CMD,如果ioctl不成功，则调用ioctl(drv->ioctl_sock, SIOCGIWRATE, &wrq)
     在Kernel中对应函数：
     cfg80211_wext_giwrate (获取当前已连接AP的发送速度)

     //每个AP对应的信息     
     struct station_info {
	u32 filled;
	u32 connected_time;
	u32 inactive_time;
	u32 rx_bytes;
	u32 tx_bytes;
	u16 llid;
	u16 plid;
	u8 plink_state;
	s8 signal;  //信号强度
	s8 signal_avg;
	struct rate_info txrate;  //发送速度
	struct rate_info rxrate;
	u32 rx_packets;
	u32 tx_packets;
	u32 tx_retries;
	u32 tx_failed;
	u32 rx_dropped_misc;
	struct sta_bss_parameters bss_param;

	int generation;
    };