获取路由器网络信息（mac，ip，router，dns，dhcp clients）
1.获取接口的mac地址
char *get_macaddr(char *ifname)
{
struct ifreq ifr;
char *ptr;
int skfd;
static char if_hw[18] = {0};
if((skfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
fprintf(stderr, "%s: open socket error\n", __func__);
return NULL;
}
strncpy(ifr.ifr_name, ifname, IF_NAMESIZE);
if(ioctl(skfd, SIOCGIFHWADDR, &ifr) < 0) {
close(skfd);
fprintf(stderr, "%s: ioctl fail\n", __func__);
return NULL;
}
ptr = (char *)&ifr.ifr_addr.sa_data;
sprintf(if_hw, "%02X:%02X:%02X:%02X:%02X:%02X",
(ptr[0] & 0377), (ptr[1] & 0377), (ptr[2] & 0377),
(ptr[3] & 0377), (ptr[4] & 0377), (ptr[5] & 0377));
close(skfd);
return if_hw;
}2.获取接口的IP地址
/*
* arguments: ifname - interface name
* if_addr - a 16-byte buffer to store ip address
* description: fetch ip address, netmask associated to given interface name
*/
int getIfIp(char *ifname, char *if_addr)
{
struct ifreq ifr;
int skfd = 0;
if((skfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
return -1;
}
strncpy(ifr.ifr_name, ifname, IF_NAMESIZE);
if (ioctl(skfd, SIOCGIFADDR, &ifr) < 0) {
close(skfd);
return -1;
}
strcpy(if_addr, inet_ntoa(((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr));
close(skfd);
return 0;
}
3.获取接口的子网掩码
/*
* arguments: ifname - interface name
* if_net - a 16-byte buffer to store subnet mask
* description: fetch subnet mask associated to given interface name
* 0 = bridge, 1 = gateway, 2 = wirelss isp
*/
int getIfNetmask(char *ifname, char *if_net)
{
struct ifreq ifr;
int skfd = 0;
if((skfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
return -1;
}
strncpy(ifr.ifr_name, ifname, IF_NAMESIZE);
if (ioctl(skfd, SIOCGIFNETMASK, &ifr) < 0) {
close(skfd);
return -1;
}
strcpy(if_net, inet_ntoa(((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr));
close(skfd);
return 0;
}
4.获取路由IP
/*
* description: write WAN default gateway accordingly
*/
static int getWanGateway(char *routerIP)
{
char buff[256];
int nl = 0 ;
struct in_addr dest;
struct in_addr gw;
int flgs, ref, use, metric;
unsigned long int d,g,m;
int find_default_flag = 0;
char sgw[16];
FILE *fp = fopen("/proc/net/route", "r");
while (fgets(buff, sizeof(buff), fp) != NULL) {
if (nl) {
int ifl = 0;
while (buff[ifl]!=' ' && buff[ifl]!='\t' && buff[ifl]!='\0')
ifl++;
buff[ifl]=0; /* interface */
if (sscanf(buff+ifl+1, "%lx%lx%X%d%d%d%lx",&d, &g, &flgs, &ref, &use, &metric, &m)!=7) {
fclose(fp);
return -1;
}
if (flgs&RTF_UP) {
dest.s_addr = d;
gw.s_addr = g;
strcpy(sgw, (gw.s_addr==0 ? "" : inet_ntoa(gw)));
if (dest.s_addr == 0) {
find_default_flag = 1;
break;
}
}
}
nl++;
}
fclose(fp);
if (find_default_flag == 1){
if(routerIP !=NULL)
strcpy(routerIP,sgw);
return 1;
}
else
return -1;
}5.获取连接到本路由器终端数的具体信息
struct ClientInfoStruct{
char name[32];
char ip[32];
char mac[32];
int rcvCount;
int sndCount;
} ;
/*
* description: write DHCP client list
*/
static int getDhcpCliList(struct ClientInfoStruct **infoArr, int *arrLen)
{
FILE *fp;
int i = 0;
int n = 0;
char buff[256];
char *dhcpclients[5];
fp = fopen("/tmp/dhcp.leases", "r");
if (NULL == fp)
return -1;
while (fgets(buff, sizeof(buff), fp) != NULL) {
char delims[] = " ";
char *result = NULL;
// printf("str = %s \n",buff);
buff[strlen(buff)-1]='\0';
result = strtok(buff,delims );
i = 0;
while( result != NULL ) {
result = strtok( NULL, delims );
dhcpclients[i] = result;
// printf( "dhcpclients[%d] is \"%s\"\n", i,dhcpclients[i]);
i++;
}
strcpy(infoArr[n]->mac,dhcpclients[0]);
strcpy(infoArr[n]->ip,dhcpclients[1]);
strcpy(infoArr[n]->name,dhcpclients[2]);
printf("infoArr[%d]->mac= %s \n",n,infoArr[n]->mac);
printf("infoArr[%d]->ip= %s \n",n,infoArr[n]->ip);
printf("infoArr[%d]->name= %s \n",n,infoArr[n]->name);
n++;
}
*arrLen = n;
fclose(fp);
return 0;
}6.获取路由器dns信息
static int getDns(int type,char *nameserver)
{
FILE *fp;
char buf[80] = {0}, ns_str[11], dns[16] = {0};
int idx = 0, req = 0;
if (1 == type)
req = 1;
else if (2 == type)
req = 2;
else
return -1;
fp = fopen("/etc/resolv.conf", "r");
if (NULL == fp)
return -1;
while(fgets(buf, sizeof(buf), fp) != NULL) {
if(strncmp(buf, "nameserver", 10) != 0)
continue;
sscanf(buf, "%s%s", ns_str, dns);
strcpy(nameserver,dns);
idx++;
if(idx == req)
break;
}
fclose(fp);
return 1;
}完整实例
注意二级指针传回值的初始化:
#include
#include
#include printf("infoArr[%d]->mac= %s \n",k,infoArr[k]->mac);
printf("infoArr[%d]->ip= %s \n",k,infoArr[k]->ip);
printf("infoArr[%d]->name= %s \n",k,infoArr[k]->name);
}
free(routerip);
routerip = NULL;
free(ip);
ip = NULL;
free(netmask);
netmask = NULL;
return 0;
}