353 lines
9.0 KiB
C
353 lines
9.0 KiB
C
|
#include <stdio.h>
|
||
|
|
#include <string.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <unistd.h>
|
||
|
|
#include <fcntl.h>
|
||
|
|
#include <sys/ioctl.h>
|
||
|
|
#include <net/if.h>
|
||
|
|
#include <linux/if_tun.h>
|
||
|
|
#include <pwd.h>
|
||
|
|
#include <grp.h>
|
||
|
|
|
||
|
|
#include <misc/version.h>
|
||
|
|
#include <misc/open_standard_streams.h>
|
||
|
|
|
||
|
|
#define PROGRAM_NAME "tunctl"
|
||
|
|
|
||
|
|
#define TUN_DEVNODE "/dev/net/tun"
|
||
|
|
|
||
|
|
struct {
|
||
|
|
int help;
|
||
|
|
int version;
|
||
|
|
int op;
|
||
|
|
char *device_name;
|
||
|
|
char *user;
|
||
|
|
char *group;
|
||
|
|
} options;
|
||
|
|
|
||
|
|
#define OP_MKTUN 1
|
||
|
|
#define OP_MKTAP 2
|
||
|
|
#define OP_RMTUN 3
|
||
|
|
#define OP_RMTAP 4
|
||
|
|
|
||
|
|
static void print_help (const char *name);
|
||
|
|
static void print_version (void);
|
||
|
|
static int parse_arguments (int argc, char *argv[]);
|
||
|
|
static int make_tuntap (const char *ifname, int is_tun, const char *user, const char *group);
|
||
|
|
static int remove_tuntap (const char *ifname, int is_tun);
|
||
|
|
|
||
|
|
int main (int argc, char *argv[])
|
||
|
|
{
|
||
|
|
int res = 1;
|
||
|
|
|
||
|
|
// open standard streams
|
||
|
|
open_standard_streams();
|
||
|
|
|
||
|
|
// parse command-line arguments
|
||
|
|
if (!parse_arguments(argc, argv)) {
|
||
|
|
fprintf(stderr, "Error: Failed to parse arguments\n");
|
||
|
|
print_help(argv[0]);
|
||
|
|
goto fail0;
|
||
|
|
}
|
||
|
|
|
||
|
|
// handle --help and --version
|
||
|
|
if (options.help) {
|
||
|
|
print_version();
|
||
|
|
print_help(argv[0]);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
if (options.version) {
|
||
|
|
print_version();
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (options.op == OP_MKTUN || options.op == OP_MKTAP) {
|
||
|
|
if (!options.user && !options.group) {
|
||
|
|
fprintf(stderr, "WARNING: with neither --user nor --group, anyone will be able to use the device!\n");
|
||
|
|
}
|
||
|
|
res = !make_tuntap(options.device_name, options.op == OP_MKTUN, options.user, options.group);
|
||
|
|
} else {
|
||
|
|
res = !remove_tuntap(options.device_name, options.op == OP_RMTUN);
|
||
|
|
}
|
||
|
|
|
||
|
|
fail0:
|
||
|
|
return res;
|
||
|
|
}
|
||
|
|
|
||
|
|
void print_help (const char *name)
|
||
|
|
{
|
||
|
|
printf(
|
||
|
|
"Usage:\n"
|
||
|
|
" %s [--help] [--version]\n"
|
||
|
|
" %s --mktun <device_name> [--user <username>] [--group <groupname>]\n"
|
||
|
|
" %s --mktap <device_name> [--user <username>] [--group <groupname>]\n"
|
||
|
|
" %s --rmtun <device_name>\n"
|
||
|
|
" %s --rmtap <device_name>\n",
|
||
|
|
name, name, name, name, name
|
||
|
|
);
|
||
|
|
}
|
||
|
|
|
||
|
|
void print_version (void)
|
||
|
|
{
|
||
|
|
printf(GLOBAL_PRODUCT_NAME" "PROGRAM_NAME" "GLOBAL_VERSION"\n"GLOBAL_COPYRIGHT_NOTICE"\n");
|
||
|
|
}
|
||
|
|
|
||
|
|
int parse_arguments (int argc, char *argv[])
|
||
|
|
{
|
||
|
|
if (argc <= 0) {
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
options.help = 0;
|
||
|
|
options.version = 0;
|
||
|
|
options.op = -1;
|
||
|
|
options.device_name = NULL;
|
||
|
|
options.user = NULL;
|
||
|
|
options.group = NULL;
|
||
|
|
|
||
|
|
for (int i = 1; i < argc; i++) {
|
||
|
|
char *arg = argv[i];
|
||
|
|
if (!strcmp(arg, "--help")) {
|
||
|
|
options.help = 1;
|
||
|
|
}
|
||
|
|
else if (!strcmp(arg, "--version")) {
|
||
|
|
options.version = 1;
|
||
|
|
}
|
||
|
|
else if (!strcmp(arg, "--mktun")) {
|
||
|
|
if (1 >= argc - i) {
|
||
|
|
fprintf(stderr, "%s: requires an argument\n", arg);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
if (options.op >= 0) {
|
||
|
|
fprintf(stderr, "%s: can only do one operation\n", arg);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
options.op = OP_MKTUN;
|
||
|
|
options.device_name = argv[i + 1];
|
||
|
|
i++;
|
||
|
|
}
|
||
|
|
else if (!strcmp(arg, "--mktap")) {
|
||
|
|
if (1 >= argc - i) {
|
||
|
|
fprintf(stderr, "%s: requires an argument\n", arg);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
if (options.op >= 0) {
|
||
|
|
fprintf(stderr, "%s: can only do one operation\n", arg);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
options.op = OP_MKTAP;
|
||
|
|
options.device_name = argv[i + 1];
|
||
|
|
i++;
|
||
|
|
}
|
||
|
|
else if (!strcmp(arg, "--rmtun")) {
|
||
|
|
if (1 >= argc - i) {
|
||
|
|
fprintf(stderr, "%s: requires an argument\n", arg);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
if (options.op >= 0) {
|
||
|
|
fprintf(stderr, "%s: can only do one operation\n", arg);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
options.op = OP_RMTUN;
|
||
|
|
options.device_name = argv[i + 1];
|
||
|
|
i++;
|
||
|
|
}
|
||
|
|
else if (!strcmp(arg, "--rmtap")) {
|
||
|
|
if (1 >= argc - i) {
|
||
|
|
fprintf(stderr, "%s: requires an argument\n", arg);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
if (options.op >= 0) {
|
||
|
|
fprintf(stderr, "%s: can only do one operation\n", arg);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
options.op = OP_RMTAP;
|
||
|
|
options.device_name = argv[i + 1];
|
||
|
|
i++;
|
||
|
|
}
|
||
|
|
else if (!strcmp(arg, "--user")) {
|
||
|
|
if (1 >= argc - i) {
|
||
|
|
fprintf(stderr, "%s: requires an argument\n", arg);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
options.user = argv[i + 1];
|
||
|
|
i++;
|
||
|
|
}
|
||
|
|
else if (!strcmp(arg, "--group")) {
|
||
|
|
if (1 >= argc - i) {
|
||
|
|
fprintf(stderr, "%s: requires an argument\n", arg);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
options.group = argv[i + 1];
|
||
|
|
i++;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
fprintf(stderr, "unknown option: %s\n", arg);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (options.help || options.version) {
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (options.op < 0) {
|
||
|
|
fprintf(stderr, "--mktun, --mktap --rmtun or --rmtap is required\n");
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
if ((options.user || options.group) && options.op != OP_MKTUN && options.op != OP_MKTAP) {
|
||
|
|
fprintf(stderr, "--user and --group only make sense for --mktun and --mktap\n");
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int make_tuntap (const char *ifname, int is_tun, const char *user, const char *group)
|
||
|
|
{
|
||
|
|
int res = 0;
|
||
|
|
|
||
|
|
if (strlen(ifname) >= IFNAMSIZ) {
|
||
|
|
fprintf(stderr, "Error: ifname too long\n");
|
||
|
|
goto fail0;
|
||
|
|
}
|
||
|
|
|
||
|
|
int fd = open(TUN_DEVNODE, O_RDWR);
|
||
|
|
if (fd < 0) {
|
||
|
|
perror("open");
|
||
|
|
fprintf(stderr, "Error: open tun failed\n");
|
||
|
|
goto fail0;
|
||
|
|
}
|
||
|
|
|
||
|
|
struct ifreq ifr;
|
||
|
|
memset(&ifr, 0, sizeof(ifr));
|
||
|
|
ifr.ifr_flags = (is_tun ? IFF_TUN : IFF_TAP);
|
||
|
|
snprintf(ifr.ifr_name, IFNAMSIZ, "%s", ifname);
|
||
|
|
|
||
|
|
if (ioctl(fd, TUNSETIFF, (void *)&ifr) < 0) {
|
||
|
|
perror("ioctl(TUNSETIFF)");
|
||
|
|
fprintf(stderr, "Error: TUNSETIFF failed\n");
|
||
|
|
goto fail1;
|
||
|
|
}
|
||
|
|
|
||
|
|
uid_t uid = -1;
|
||
|
|
gid_t gid = -1;
|
||
|
|
|
||
|
|
if (user) {
|
||
|
|
long bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
|
||
|
|
if (bufsize < 0) {
|
||
|
|
bufsize = 16384;
|
||
|
|
}
|
||
|
|
|
||
|
|
char *buf = malloc(bufsize);
|
||
|
|
if (!buf) {
|
||
|
|
fprintf(stderr, "Error: malloc failed\n");
|
||
|
|
goto fail1;
|
||
|
|
}
|
||
|
|
|
||
|
|
struct passwd pwd;
|
||
|
|
struct passwd *res;
|
||
|
|
getpwnam_r(user, &pwd, buf, bufsize, &res);
|
||
|
|
if (!res) {
|
||
|
|
fprintf(stderr, "Error: getpwnam_r failed\n");
|
||
|
|
free(buf);
|
||
|
|
goto fail1;
|
||
|
|
}
|
||
|
|
|
||
|
|
uid = pwd.pw_uid;
|
||
|
|
free(buf);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (group) {
|
||
|
|
long bufsize = sysconf(_SC_GETGR_R_SIZE_MAX);
|
||
|
|
if (bufsize < 0) {
|
||
|
|
bufsize = 16384;
|
||
|
|
}
|
||
|
|
|
||
|
|
char *buf = malloc(bufsize);
|
||
|
|
if (!buf) {
|
||
|
|
fprintf(stderr, "Error: malloc failed\n");
|
||
|
|
goto fail1;
|
||
|
|
}
|
||
|
|
|
||
|
|
struct group grp;
|
||
|
|
struct group *res;
|
||
|
|
getgrnam_r(group, &grp, buf, bufsize, &res);
|
||
|
|
if (!res) {
|
||
|
|
fprintf(stderr, "Error: getgrnam_r failed\n");
|
||
|
|
free(buf);
|
||
|
|
goto fail1;
|
||
|
|
}
|
||
|
|
|
||
|
|
gid = grp.gr_gid;
|
||
|
|
free(buf);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (ioctl(fd, TUNSETOWNER, uid) < 0) {
|
||
|
|
perror("ioctl(TUNSETOWNER)");
|
||
|
|
fprintf(stderr, "Error: TUNSETOWNER failed\n");
|
||
|
|
goto fail1;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (ioctl(fd, TUNSETGROUP, gid) < 0) {
|
||
|
|
perror("ioctl(TUNSETGROUP)");
|
||
|
|
fprintf(stderr, "Error: TUNSETGROUP failed\n");
|
||
|
|
goto fail1;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (ioctl(fd, TUNSETPERSIST, (void *)1) < 0) {
|
||
|
|
perror("ioctl(TUNSETPERSIST)");
|
||
|
|
fprintf(stderr, "Error: TUNSETPERSIST failed\n");
|
||
|
|
goto fail1;
|
||
|
|
}
|
||
|
|
|
||
|
|
res = 1;
|
||
|
|
|
||
|
|
fail1:
|
||
|
|
close(fd);
|
||
|
|
fail0:
|
||
|
|
return res;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int remove_tuntap (const char *ifname, int is_tun)
|
||
|
|
{
|
||
|
|
int res = 0;
|
||
|
|
|
||
|
|
if (strlen(ifname) >= IFNAMSIZ) {
|
||
|
|
fprintf(stderr, "Error: ifname too long\n");
|
||
|
|
goto fail0;
|
||
|
|
}
|
||
|
|
|
||
|
|
int fd = open(TUN_DEVNODE, O_RDWR);
|
||
|
|
if (fd < 0) {
|
||
|
|
perror("open");
|
||
|
|
fprintf(stderr, "Error: open tun failed\n");
|
||
|
|
goto fail0;
|
||
|
|
}
|
||
|
|
|
||
|
|
struct ifreq ifr;
|
||
|
|
memset(&ifr, 0, sizeof(ifr));
|
||
|
|
ifr.ifr_flags = (is_tun ? IFF_TUN : IFF_TAP);
|
||
|
|
snprintf(ifr.ifr_name, IFNAMSIZ, "%s", ifname);
|
||
|
|
|
||
|
|
if (ioctl(fd, TUNSETIFF, (void *)&ifr) < 0) {
|
||
|
|
perror("ioctl(TUNSETIFF)");
|
||
|
|
fprintf(stderr, "Error: TUNSETIFF failed\n");
|
||
|
|
goto fail1;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (ioctl(fd, TUNSETPERSIST, (void *)0) < 0) {
|
||
|
|
perror("ioctl(TUNSETPERSIST)");
|
||
|
|
fprintf(stderr, "Error: TUNSETPERSIST failed\n");
|
||
|
|
goto fail1;
|
||
|
|
}
|
||
|
|
|
||
|
|
res = 1;
|
||
|
|
|
||
|
|
fail1:
|
||
|
|
close(fd);
|
||
|
|
fail0:
|
||
|
|
return res;
|
||
|
|
}
|