libtun 0.1.0

a cross-platform(macosx, linux) tunnel library
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38

#include <sys/sys_domain.h>
#include <sys/kern_control.h>
#include <net/if_utun.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>

int utun_open(int* fdOut, int idx) {
    struct ctl_info ctlInfo;
    strlcpy(ctlInfo.ctl_name, UTUN_CONTROL_NAME, sizeof(ctlInfo.ctl_name));
    int fd = socket(PF_SYSTEM, SOCK_DGRAM, SYSPROTO_CONTROL);
    if (fd < 0) {
        return errno;
    }

    struct sockaddr_ctl sc;
    if (ioctl(fd, CTLIOCGINFO, &ctlInfo) == -1) {
        close(fd);
        return errno;
    }

    sc.sc_id = ctlInfo.ctl_id;
    sc.sc_len = sizeof(sc);
    sc.sc_family = AF_SYSTEM;
    sc.ss_sysaddr = AF_SYS_CONTROL;
    sc.sc_unit = idx+1;

    if (connect(fd, (struct sockaddr *)&sc, sizeof(sc)) < 0) {
        close(fd);
        return errno;
    }

    *fdOut = fd;
    return 0;
}