创建 tun 设备时出错(参数无效)
Error creating tun device (Invalid argument)
我在这里引用示例:https://www.kernel.org/doc/Documentation/networking/tuntap.txt (which is quite old), but the link here suggests that the same thing should work as well: (http://backreference.org/2010/03/26/tuntap-interface-tutorial/)。
否则,我几乎找不到最新的文档。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <linux/if.h>
#include <linux/if_tun.h>
int main(void) {
char *clonedev = "/dev/net/tun";
int fd, err;
char * dev_name = "tun0";
struct ifreq ifr;
if( (fd = open(clonedev, O_RDWR)) < 0 ) {
exit(1);
}
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, dev_name, IFNAMSIZ);
printf("Opened %s \n", ifr.ifr_name);
if( (err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0 ) {
printf("Failed to creat tun device (errno is %d)\n",
errno);
perror("ioctl");
close(fd);
exit(1);
}
printf("device created");
}
输出:
Opened tun0
Failed to creat tun device (errno is 22)
ioctl: Invalid argument
编辑:Grepping OpenVPN 源代码显示相同的用法:
src/openvpn/tun.c:1681: if (ioctl (tt->fd, TUNSETIFF, (void *) &ifr) < 0)
你没有这样的东西,你的两个链接都有:
ifr.ifr_flags = IFF_TUN;
似乎是获得无效参数错误的一种非常合理的方法。
你错过了示例中的这一行
ifr.ifr_flags = flags; /* IFF_TUN or IFF_TAP, plus maybe IFF_NO_PI */
所以,在 ioctl() 之前缺少这个
ifr.ifr_flags = IFF_TUN;
或
ifr.ifr_flags = IFF_TAP;
我在这里引用示例:https://www.kernel.org/doc/Documentation/networking/tuntap.txt (which is quite old), but the link here suggests that the same thing should work as well: (http://backreference.org/2010/03/26/tuntap-interface-tutorial/)。 否则,我几乎找不到最新的文档。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <linux/if.h>
#include <linux/if_tun.h>
int main(void) {
char *clonedev = "/dev/net/tun";
int fd, err;
char * dev_name = "tun0";
struct ifreq ifr;
if( (fd = open(clonedev, O_RDWR)) < 0 ) {
exit(1);
}
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, dev_name, IFNAMSIZ);
printf("Opened %s \n", ifr.ifr_name);
if( (err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0 ) {
printf("Failed to creat tun device (errno is %d)\n",
errno);
perror("ioctl");
close(fd);
exit(1);
}
printf("device created");
}
输出:
Opened tun0
Failed to creat tun device (errno is 22)
ioctl: Invalid argument
编辑:Grepping OpenVPN 源代码显示相同的用法:
src/openvpn/tun.c:1681: if (ioctl (tt->fd, TUNSETIFF, (void *) &ifr) < 0)
你没有这样的东西,你的两个链接都有:
ifr.ifr_flags = IFF_TUN;
似乎是获得无效参数错误的一种非常合理的方法。
你错过了示例中的这一行
ifr.ifr_flags = flags; /* IFF_TUN or IFF_TAP, plus maybe IFF_NO_PI */
所以,在 ioctl() 之前缺少这个
ifr.ifr_flags = IFF_TUN;
或
ifr.ifr_flags = IFF_TAP;