Linux下测试网线是否连接的源码

#include <stdio.h> #include <string.h> #include <errno.h> #include <fcntl.h> #include <getopt.h> #include <stdlib.h> #include <unistd.h> #include <sys/socket.h> #include <sys/ioctl.h> #include <net/if.h> #include <linux/sockios.h> #include <linux/types.h> #include <linux/ethtool.h> //typedef unsigned short u16; //typedef unsigned int u32; //typedef unsigned char u8; int detect_mii(int skfd, char *ifname) { struct ifreq ifr; unsigned short *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 = (unsigned short *)(&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; struct ethtool_value edata; memset(&ifr, 0, sizeof(ifr)); edata.cmd = ETHTOOL_GLINK; 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 main(int argc, char **argv) { int skfd = -1; char *ifname; int retval; if( argv[1] ) ifname = argv[1]; else ifname = "eth0"; /* Open a socket. */ if (( skfd = socket( AF_INET, SOCK_DGRAM, 0 ) ) < 0 ) { printf("socket error\n"); exit(-1); } retval = detect_ethtool(skfd, ifname); if (retval == 2) retval = detect_mii(skfd, ifname); close(skfd); if (retval == 2) printf("Could not determine status\n"); if (retval == 1) printf("Link down\n"); if (retval == 0) printf("Link up\n"); return retval; }