#include <stdio.h>

#include <string.h>

#include <unistd.h>

#include <fcntl.h>

#include <sys/ioctl.h>

#include <linux/if.h>

#include <linux/if_tun.h>

#include "wg.h"

int

wg_tun_open(const char *dev_name)

{

struct ifreq ifr;

int fd;

fd = open("/dev/net/tun", O_RDWR);

if (fd < 0) {

perror("open /dev/net/tun");

return -1;

}

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

ifr.ifr_flags = IFF_TUN | IFF_NO_PI;

if (dev_name && *dev_name) {

strncpy(ifr.ifr_name, dev_name, IFNAMSIZ - 1);

}

if (ioctl(fd, TUNSETIFF, &ifr) < 0) {

perror("ioctl TUNSETIFF");

close(fd);

return -1;

}

fprintf(stderr, "TUN device created: %s\n", ifr.ifr_name);

return fd;

}

ssize_t

wg_tun_read(int fd, uint8_t *buf, size_t size)

{

ssize_t n = read(fd, buf, size);

if (n < 0) {

perror("tun read");

}

return n;

}

ssize_t

wg_tun_write(int fd, const uint8_t *buf, size_t size)

{

ssize_t n = write(fd, buf, size);

if (n < 0) {

perror("tun write");

}

return n;

}