/**
* linux TUN 例子 代码来至
* http://hi.baidu.com/zkheartboy/blog/item/e96acf33508e4a40ad4b5f88.html和
* http://blog.csdn.net/Z_man/archive/2009/05/26/4216530.aspx
* 建立一个tun0的虚拟网卡进行通信,程序关闭后将消失。
* ping 10.0.0.1
* Documentation/networking/tuntap.txt
* br_select.c bridge based on select system call.
* br_sigio.c bridge based on async io and SIGIO signal.
* http://hi.baidu.com/zkheartboy/blog/item/e96acf33508e4a40ad4b5f88.html
* http://blogold.chinaunix.net/u3/114446/showart_2245279.html
* http://www.ibm.com/developerworks/cn/linux/l-tuntap/index.html
*/
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
/**
* 激活接口
*/
int interface_up(char *interface_name)
{
int s;
if((s = socket(PF_INET,SOCK_STREAM,0)) < 0)
{
printf("Error create socket :%d\n", errno);
return -1;
}
struct ifreq ifr;
strcpy(ifr.ifr_name,interface_name);
short flag;
flag = IFF_UP;
if(ioctl(s, SIOCGIFFLAGS, &ifr) < 0)
{
printf("Error up %s :%d\n",interface_name, errno);
return -1;
}
ifr.ifr_ifru.ifru_flags |= flag;
if(ioctl(s, SIOCSIFFLAGS, &ifr) < 0)
{
printf("Error up %s :%d\n",interface_name, errno);
return -1;
}
return 0;
}
#if 0
/**
* 设置接口ip地址
*/
int set_ipaddr(char *interface_name, char *ip)
{
int s;
if((s = socket(PF_INET, SOCK_STREAM, 0)) < 0)
{
printf("Error up %s :%d\n",interface_name, errno);
return -1;
}
struct ifreq ifr;
strcpy(ifr.ifr_name, interface_name);
struct sockaddr_in addr;
bzero(&addr, sizeof(struct sockaddr_in));
addr.sin_family = PF_INET;
inet_aton(ip, &addr.sin_addr);
memcpy(&ifr.ifr_ifru.ifru_addr, &addr, sizeof(struct sockaddr_in));
if(ioctl(s, SIOCSIFADDR, &ifr) < 0)
{
printf("Error set %s ip :%d\n",interface_name, errno);
return -1;
}
return 0;
}
#endif
/**
* 创建接口
*/
int tun_create(char *dev, int flags)
{
struct ifreq ifr;
int fd, err;
if ((fd = open("/dev/net/tun", O_RDWR)) < 0)
{
printf("Error :%d\n", errno);
return -1;
}
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags |= flags;
if (*dev != '\0')
{
strncpy(ifr.ifr_name, dev, IFNAMSIZ);
}
if ((err = ioctl(fd, TUNSETIFF, (void *)&ifr)) < 0)
{
printf("Error :%d\n", errno);
close(fd);
return -1;
}
strcpy(dev, ifr.ifr_name);
return fd;
}
/**
* 增加到10.0.0.1的路由
* 同命令:route add 10.0.0.1 dev tun0
*/
int route_add(char * interface_name)
{
int skfd;
struct rtentry rt;
struct sockaddr_in dst;
//struct sockaddr_in gw;
struct sockaddr_in genmask;
memset(&rt, 0, sizeof(rt));
genmask.sin_addr.s_addr = inet_addr("255.255.255.255");
bzero(&dst,sizeof(struct sockaddr_in));
dst.sin_family = PF_INET;
dst.sin_addr.s_addr = inet_addr("10.0.0.1");
rt.rt_metric = 0;
rt.rt_dst = *(struct sockaddr*) &dst;
rt.rt_genmask = *(struct sockaddr*) &genmask;
rt.rt_dev = interface_name;
rt.rt_flags = RTF_UP | RTF_HOST ;
skfd = socket(AF_INET, SOCK_DGRAM, 0);
if(ioctl(skfd, SIOCADDRT, &rt) < 0)
{
printf("Error route add :%d\n", errno);
return -1;
}
return 0;
}
int main(int argc, char *argv[])
{
int tun, ret;
char tun_name[IFNAMSIZ];
unsigned char buf[4096];
unsigned char ip[4];
tun_name[0] = '\0';
tun = tun_create(tun_name, IFF_TUN | IFF_NO_PI);
if (tun < 0)
{
return 1;
}
printf("TUN name is %s\n", tun_name);
//激活虚拟网卡增加到虚拟网卡的路由
interface_up(tun_name);
route_add(tun_name);
while (1) {
ret = read(tun, buf, sizeof(buf));
printf("read %d bytes\n", ret);
int i;
for(i=0;i
测试方法:
1 先编译运行此程序,监听数据的读写。
2 开启另外一个终端,执行ping命令,就是本地发一个测试包到10.0.0.1
即可看到收到和接收的数据包IP包了。
http://blog.csdn.net/xuxinyl/article/details/6454536