用ioclt 来设置路由

#include <errno.h>

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <net/route.h>

#include <sys/types.h>

#include <sys/ioctl.h>



int main(char** args) {

    int sockfd;

    struct rtentry route;

    struct sockaddr_in *addr;

    int err = 0;

   

    // create the socket

    if((sockfd = socket(AF_INET, SOCK_DGRAM, 0))<0){

        perror("socket");

        exit(1);

    }



    memset(&route, 0, sizeof(route));

    addr = (struct sockaddr_in*) &route.rt_gateway;

    addr->sin_family = AF_INET;

    //addr->sin_addr.s_addr = inet_addr("192.168.100.1");

    addr->sin_addr.s_addr = inet_addr("0.0.0.0"); 

    addr = (struct sockaddr_in*) &route.rt_dst;

    addr->sin_family = AF_INET;

    addr->sin_addr.s_addr = inet_addr("192.168.1.0");

    addr = (struct sockaddr_in*) &route.rt_genmask;

    addr->sin_family = AF_INET;

    addr->sin_addr.s_addr = inet_addr("255.255.255.0");

    //route.rt_flags = RTF_UP | RTF_GATEWAY;

    route.rt_flags = RTF_UP  ;

    route.rt_metric = 0;

    route.rt_dev    = "eth0";

    if ((err = ioctl(sockfd, SIOCADDRT, &route)) != 0) {

        perror("SIOCADDRT failed");

        exit(1);

    }

}