Linux下wifi工具wpa_cli使用

wpa_cli使用

• 掃描
• 查看掃描結果
• 添加network
• 設置SSID
• 選擇某個network
• 查看networks
• 使能某個network
• 查詢連接情況
• 自動分配IP地址
• API Demo

掃描

[root@demo]# wpa_cli -i wlan0 scan
OK

查看掃描結果

• 注意返回格式
  bssid ’\t’ frequency ’\t’ signal level ’\t’ flags ’\t’ ssid ’\n’
  這中間是用製表符==’\t’隔開的,最後一個字符是’\n’==

[root@demo]# wpa_cli -i wlan0 scan_result
bssid / frequency / signal level / flags / ssid
dc:fe:18:19:bf:4d       2462    -47     [WPA-PSK-CCMP][WPA2-PSK-CCMP][ESS]      TP-LINK_BF4D
34:0a:98:97:9a:14       2427    -66     [WPA-PSK-CCMP+TKIP][WPA2-PSK-CCMP+TKIP][WPS][ESS]       CMCC-3KUu
d4:62:ea:80:84:10       2462    -71     [WPA2-PSK-CCMP][WPS][ESS]       HUAWEI-H
68:db:54:6b:25:8f       2422    -75     [WPA-PSK-CCMP+TKIP][WPA2-PSK-CCMP+TKIP][ESS]    @PHICOMM_8D
50:fa:84:88:6a:85       2462    -75     [WPA-PSK-CCMP+TKIP][WPA2-PSK-CCMP+TKIP][ESS]    TP-LINK_6856
d0:76:e7:35:4a:03       2437    -77     [WPA-PSK-CCMP][WPA2-PSK-CCMP][ESS]      TP-LINK_903

添加network

[root@demo]#wpa_cli -i wlan0 add_network
0
[root@demo]#wpa_cli -i wlan0 add_network
1

設置 SSID

• [WPA-PSK-CCMP+TKIP][WPA2-PSK-CCMP+TKIP][ESS] (wpa加密)，wifi名稱是name, wifi密碼是psk

[root@demo]$ wpa_cli -i wlan0 set_network 0 ssid '"name"'  
[root@demo]$ wpa_cli -i wlan0 set_network 0 psk '"psk"'  
[root@demo]$ wpa_cli -i wlan0 enable_network 0

• [WEP][ESS]wep加密

[root@demo]$ wpa_cli -i wlan0 set_network 0 ssid '"name"'  
[root@demo]$ wpa_cli -i wlan0 set_network 0 key_mgmt NONE  
[root@demo]$ wpa_cli -i wlan0 set_network 0 wep_key0 '"psk"'  
[root@demo]$ wpa_cli -i wlan0 enable_network 0  

• [ESS]無加密連接,wifi名稱是name

[root@demo]	$ wpa_cli -i wlan0 set_network 0 ssid '"name"'  
[root@demo]	$ wpa_cli -i wlan0 set_network 0 key_mgmt NONE  
[root@demo]$ wpa_cli -i wlan0 enable_network 0 

查看networks

[root@demo]	$ wpa_cli list_networks
Selected interface 'wlan0'
network		id	/ssid	/bssid/	flags
0					any			[CURRENT]
1					any			[DISABLE]

選擇某個network

[root@demo]	$ wpa_cli select_netowrk 0
Selected interface 'wlan0'
OK

使能某個network

[root@demo]	$ wpa_cli -i wlan0 enable_network 0
OK  

查詢連接情況

[root@demo]	$ wpa_cli -i wlan0 status
 //返回內容請見下圖 

自動分配IP地址

[root@demo]	$ udhcpc -i wlan0
udhcpc(v1.23.2) started
Sending discover...
Sending select for 192.168.0.104...
Lease of 192.168.0.104 obtained, lease time 7200
deleting routers
adding dns

API Demo

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>


static char wifi_ssid[16][128];
static char *wifi_name[16];
//----------------------------------------------------------------------
// D E F I N I T I O N
//----------------------------------------------------------------------


//----------------------------------------------------------------------
// L O C A L  D E F I N I T I O N
//----------------------------------------------------------------------
static const char *SCAN        ="wpa_cli -i wlan0 scan";
static const char *SCAN_RES    ="wpa_cli -i wlan0 scan_result";
static const char *ADD_NETWORK = "wpa_cli -i wlan0 add_network";
static const char *SELECT_NETWORK   ="wpa_cli -i wlan0 select_network";
static const char *STATUS       ="wpa_cli -i wlan0 status";
static const char *SET_SSID = "wpa_cli -i wlan0 set_network 0 ssid";
static const char *SET_PASSWORD = "wpa_cli -i wlan0 set_network 0 psk";
static const char *ENABLE_NETWORK  = "wpa_cli -i wlan0 enable_network 0";
static const char *UDHCPC_NETWORK  = "udhcpc -i wlan0";

//----------------------------------------------------------------------
// L O C A L  F U N C T I O N  D E F I N I T I O N
//----------------------------------------------------------------------
static int wifi_scan(void);
static void wifi_scan_result(char (*ssid_buf)[128]);
//----------------------------------------------------------------------
// L O C A L  F U N C T I O N  I M P L E M E N T A T I O N
//----------------------------------------------------------------------

//----------------------------------------------------------------------
// function: wifi_scan
// parameter: none
// return:   1 -- scan OK    0 -- scan failed
//----------------------------------------------------------------------
static int wifi_scan(void)
{
	FILE *fp;
	char buf[8]={0};
	if((fp = popen(SCAN,"r"))==NULL)
	{
		perror("SCAN");
		exit(1);
	}
	while(fgets(buf,sizeof(buf),fp)!=NULL) //fgets()此處是否會阻塞？
	{
		printf("%s\n",buf);
		if(strstr(buf,"OK")!=NULL)
		{
			printf("close fp and return\n");
			pclose(fp);
			return 1;
		}
	}
	return 0;
}

//----------------------------------------------------------------------
// function:  set_noblock_read
// statement: set fgets noblock read mode
// parameter: FILE* fstream, which is popen func returned
// return:    none
//----------------------------------------------------------------------
static void set_noblock_read(FILE *fstream)
{
	int fd;
	int flags;
	fd = fileno(fstream);
	flags = fcntl(fd,F_GETFL,0);
	flags |= O_NONBLOCK;
	fcntl(fd,F_SETFL,flags);
	return ;
}

//----------------------------------------------------------------------
// function:  wifi_scan_res
// statement: show scan result, get ssid to the ssid buf
// parameter: wifi_ssid buf
// return:    none
//----------------------------------------------------------------------
static void wifi_scan_result(char (*ssid_buf)[128])
{
	FILE *fp;
	char *p_n=NULL;
	char *p_ssid_end = NULL;
	char *p_ssid_start=NULL;
	char buf[4096]={0};
	int flags;
	int ssid_index=0;
	if((fp=popen(SCAN_RES,"r"))==NULL)
	{
		perror("SCAN_RES");
		exit(1);
	}
	int fd = fileno(fp); //把文件指針轉換成文件描述符用fileno函數
	flags = fcntl(fd,F_GETFL,0);
	flags |= O_NONBLOCK;   //O_NONBLOCK = 04000
	fcntl(fd,F_SETFL,flags);
	sleep(1);  //這裏必須要等待一下，否則fgets立即返回NULL,捕獲不到數據
	while(fgets(buf,sizeof(buf),fp)!=NULL) //wifi掃描不到是否意味着就一直阻塞在這裏？比如在沒有WiFi的地方
	{
		//printf("%s",buf);
		if(strstr(buf,(const char*)"bssid")!=NULL) //忽略第一行
		{
			continue;
		}
		if((p_n = strstr(buf,"\n"))!=NULL) //注意，\n是接收到的最後一個字符
		{
			p_ssid_end = p_n-1; //'\n前面一個字符'
			while(*p_n !='\t') //中間是用'\t'製表符隔開的
			{
				p_n--;
			}
			p_ssid_start = p_n; //'\t'
			strncpy(ssid_buf[ssid_index],(p_ssid_start+1),(p_ssid_end-p_ssid_start));
			printf("%s\n",ssid_buf[ssid_index]);
			ssid_index++;
		}
	}
	printf("fgets() return without block and close fp\n");
	pclose(fp);

	return ;
}

//----------------------------------------------------------------------
// function:  wifi_add_network
// statement: add net work, there where a network list, wpa_cli list_networks
//            can see how many network add add in the lsit, but there is only
//            one in the current state.
// parameter: null
// return:    the network id in the system
//
//----------------------------------------------------------------------
static int wifi_add_network(void)
{
	FILE *fp;
	char buf[8]={0};
	if((fp = popen(ADD_NETWORK,"r"))==NULL)
	{
		perror("ADD_NETWORK");
		exit(1);
	}
	while(fgets(buf,sizeof(buf),fp)!=NULL)
	{
		printf("%s\n",buf);
	}
	return 0;
}

//----------------------------------------------------------------------
// function:  wifi_set_ssid(char *ssid_name)
// statement: set ssid name
//
// parameter:
// return:    1 -- success
//            0 -- failed
//----------------------------------------------------------------------
static int wifi_set_ssid(char *ssid_name)
{
	FILE *fp;
	char buf[128]={0};
	char cmd[128]="";
	strcat(cmd,SET_SSID);
	strcat(cmd," '\"");
	strcat(cmd,ssid_name);
	strcat(cmd,"\"'");
	printf("%s\n",cmd);
	if((fp=popen(cmd,"r"))==NULL)
	{
		perror("set ssid failed");
		exit(1);
	}
	set_noblock_read(fp); //no block read
	sleep(1);
	while(fgets(buf,sizeof(buf),fp)!=NULL)
	{
		printf("%s\n",buf);
		if(strstr(buf,"OK")!=NULL)
		{
			pclose(fp);
			return 1;
		}
	}
	pclose(fp);
	return 0;
}

//----------------------------------------------------------------------
// function:  wifi_set_password(char *password)
// statement: set password
//
// parameter:
// return:    1 -- success
//            0 -- failed
//----------------------------------------------------------------------
static int wifi_set_password(char *password)
{
	FILE *fp;
	char buf[128]={0};
	char cmd[128]="";
	strcat(cmd,SET_PASSWORD);
	strcat(cmd," '\"");
	strcat(cmd,password);
	strcat(cmd,"\"'");
	printf("%s\n",cmd);
	if((fp=popen(cmd,"r"))==NULL)
	{
		perror("set password failed");
		exit(1);
	}
	set_noblock_read(fp); //no block read
	sleep(1);
	while(fgets(buf,sizeof(buf),fp)!=NULL)
	{
		printf("%s\n",buf);
		if(strstr(buf,"OK")!=NULL)
		{
			pclose(fp);
			return 1;
		}
	}
	pclose(fp);
	return 0;
}

//----------------------------------------------------------------------
// function:  wifi_enable_netword(char *password)
// statement: after set ssid and psk, need to enable network.
//            then can use udhcpc -i wlan0
// parameter:
// return:    1 -- success
//            0 -- failed
//----------------------------------------------------------------------
static int wifi_enable_network(void)
{
	FILE *fp;
	char buf[8]={0};
	fp=popen(ENABLE_NETWORK,"r");
	while(fgets(buf,8,fp)!=NULL)
	{
		printf("%s\n",buf);
		if(strstr(buf,"OK")!=NULL)
		{
			pclose(fp);
			return 1;
		}
	}
	pclose(fp);
	return 0;
}

//----------------------------------------------------------------------
// M I A N   F U N C T I O N
//----------------------------------------------------------------------
int main()
{
	memset(wifi_ssid,0,sizeof(char)*16*128);
	wifi_scan();
	sleep(2);
	wifi_scan_result(wifi_ssid);
	wifi_add_network();
	wifi_set_ssid("TP-LINK_BF4D");
	wifi_set_password("wjj198712162803");
	wifi_enable_network();
	exit(1);
}