通过socket获取网卡状态

刺骨的言语ヽ痛彻心扉 2022-05-08 09:14 525阅读 0赞

#include <stdio.h>
    #include <string.h>
    #include <errno.h>
    #include <fcntl.h>
    #include <getopt.h>
    #include <sys/socket.h>
    #include <sys/ioctl.h>
    #include <net/if.h>
    #include <stdlib.h>
    #include <unistd.h>
    #include <linux/ethtool.h>
    #include <linux/sockios.h>
     
    typedef unsigned short u16;
    typedef unsigned int u32;
    typedef unsigned char u8;
     
     /* 获取MII phy的地址 然后读取phy寄存器的值*/
    int detect_mii(int skfd, char *ifname)
    {
       struct ifreq ifr;
       u16 *data, mii_val;
       unsigned phy_id;
     
       /* Get the vitals from the interface. */
       strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
     
       if (ioctl(skfd, SIOCGMIIPHY, &ifr) < 0)
          {
             fprintf(stderr, "SIOCGMIIPHY on %s failed: %s\n", ifname, strerror(errno));
             (void) close(skfd);
             return 2;
          }
     
       data = (u16 *)(&ifr.ifr_data);
       phy_id = data[0];
       data[1] = 1;
     
       if (ioctl(skfd, SIOCGMIIREG, &ifr) < 0)
         {
            fprintf(stderr, "SIOCGMIIREG on %s failed: %s\n", ifr.ifr_name, strerror(errno));
            return 2;
         }
     
       mii_val = data[3];
       return(((mii_val & 0x0016) == 0x0004) ? 0 : 1);
    }
     
    int detect_ethtool(int skfd, char *ifname)
    {
       struct ifreq ifr; /* ifreq里包含了接口的所有信息，比如接口名，地址等等 */
       struct ethtool_value edata;
       
       memset(&ifr, 0, sizeof(ifr));
       edata.cmd = ETHTOOL_GLINK;
       
       /* 设置要查询的网卡接口名称 */
       strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)-1);
       ifr.ifr_data = (char *) &edata;
     
       if (ioctl(skfd, SIOCETHTOOL, &ifr) == -1)
         {
            printf("ETHTOOL_GLINK failed: %s\n", strerror(errno));
            return 2;
         }
     
       return (edata.data ? 0 : 1);
    }
     
    int CheckNet()
    {
    	int skfd = -1;
    	/* 如果这里所填的名字没有对应的phy（比如phy2），则会报错No such device */
    	char *ifname = "eth0";
    	int retval;
     
    	/* Open a socket. */
    	if (( skfd = socket( AF_INET, SOCK_DGRAM, 0 ) ) < 0 )
    	{
    		printf("socket error\n");
    		exit(-1);
    	}
     
    	/* 这里使用两种方式来获取网卡的状态 */
    	retval = detect_ethtool(skfd, ifname); /* 使用SIOCETHTOOL方式获取 */
    	if (retval == 2)
    	{
    		retval = detect_mii(skfd, ifname); /*使用SIOCGMIIPHY方式获取，即先获取指定phy的地址，然后读指定的寄存器*/
    	}
    	
    	close(skfd);
     
    	return retval;
    }
     
    //int main(int argc, char **argv)
    int phyOperate(void* arg)
    {
    	int ret = -1,retold = -1;
    	while(1)
    	{
    		ret = CheckNet();
    		/*如果状态发生变化才打印*/
    		if(ret != retold)
    		{
    			retold = ret;
    			if (ret == 2)
    				printf("Could not determine status\n");
    			if (ret == 1)
    				printf("Link down %s pid = %d\n",(char*)arg,getpid());
    			if (ret == 0)
    				printf("Link up %s pid = %d\n",(char*)arg,getpid());
    		}
    	}
    }
    
    /*多个线程检测网卡状态*/
    int main()
    {
    	int i = 0;
    	pthread_t thread1,thread2,thread3,thread4;
    	
    	pthread_create(&thread1,NULL,phyOperate,"thread1");
    	pthread_create(&thread2,NULL,phyOperate,"thread2");
    	pthread_create(&thread3,NULL,phyOperate,"thread3");
    	//pthread_create(&thread4,NULL,phyOperate,"thread4");
    	
    	/*不加下面的话线程会结束*/
    	pthread_join(thread1,"thread1");
    	pthread_join(thread2,"thread2");
    	pthread_join(thread3,"thread3");
    	//pthread_join(thread4,"thread4");
    
    }