int main(int argc, char *argv[]) {
_cleanup_(manager_freep) Manager *m = NULL;
const char *user = "******";
uid_t uid;
gid_t gid;
int r;
log_set_target(LOG_TARGET_AUTO);
log_parse_environment();
log_open();
if (argc != 1) {
log_error("This program takes no arguments.");
r = -EINVAL;
goto finish;
}
umask(0022);
r = mac_selinux_init();
if (r < 0) {
log_error_errno(r, "SELinux setup failed: %m");
goto finish;
}
r = get_user_creds(&user, &uid, &gid, NULL, NULL);
if (r < 0) {
log_error_errno(r, "Cannot resolve user name %s: %m", user);
goto finish;
}
/* Always create the directory where resolv.conf will live */
r = mkdir_safe_label("/run/systemd/resolve", 0755, uid, gid, false);
if (r < 0) {
log_error_errno(r, "Could not create runtime directory: %m");
goto finish;
}
/* Drop privileges, but only if we have been started as root. If we are not running as root we assume all
* privileges are already dropped. */
if (getuid() == 0) {
/* Drop privileges, but keep three caps. Note that we drop those too, later on (see below) */
r = drop_privileges(uid, gid,
(UINT64_C(1) << CAP_NET_RAW)| /* needed for SO_BINDTODEVICE */
(UINT64_C(1) << CAP_NET_BIND_SERVICE)| /* needed to bind on port 53 */
(UINT64_C(1) << CAP_SETPCAP) /* needed in order to drop the caps later */);
if (r < 0)
goto finish;
}
assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, SIGUSR1, SIGUSR2, SIGRTMIN+1, -1) >= 0);
r = manager_new(&m);
if (r < 0) {
log_error_errno(r, "Could not create manager: %m");
goto finish;
}
r = manager_start(m);
if (r < 0) {
log_error_errno(r, "Failed to start manager: %m");
goto finish;
}
/* Write finish default resolv.conf to avoid a dangling symlink */
(void) manager_write_resolv_conf(m);
/* Let's drop the remaining caps now */
r = capability_bounding_set_drop(0, true);
if (r < 0) {
log_error_errno(r, "Failed to drop remaining caps: %m");
goto finish;
}
sd_notify(false,
"READY=1\n"
"STATUS=Processing requests...");
r = sd_event_loop(m->event);
if (r < 0) {
log_error_errno(r, "Event loop failed: %m");
goto finish;
}
sd_event_get_exit_code(m->event, &r);
finish:
sd_notify(false,
"STOPPING=1\n"
"STATUS=Shutting down...");
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}
int import_fork_tar_x(const char *path, pid_t *ret) {
_cleanup_close_pair_ int pipefd[2] = { -1, -1 };
pid_t pid;
int r;
assert(path);
assert(ret);
if (pipe2(pipefd, O_CLOEXEC) < 0)
return log_error_errno(errno, "Failed to create pipe for tar: %m");
pid = fork();
if (pid < 0)
return log_error_errno(errno, "Failed to fork off tar: %m");
if (pid == 0) {
int null_fd;
uint64_t retain =
(1ULL << CAP_CHOWN) |
(1ULL << CAP_FOWNER) |
(1ULL << CAP_FSETID) |
(1ULL << CAP_MKNOD) |
(1ULL << CAP_SETFCAP) |
(1ULL << CAP_DAC_OVERRIDE);
/* Child */
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
pipefd[1] = safe_close(pipefd[1]);
if (dup2(pipefd[0], STDIN_FILENO) != STDIN_FILENO) {
log_error_errno(errno, "Failed to dup2() fd: %m");
_exit(EXIT_FAILURE);
}
if (pipefd[0] != STDIN_FILENO)
pipefd[0] = safe_close(pipefd[0]);
null_fd = open("/dev/null", O_WRONLY|O_NOCTTY);
if (null_fd < 0) {
log_error_errno(errno, "Failed to open /dev/null: %m");
_exit(EXIT_FAILURE);
}
if (dup2(null_fd, STDOUT_FILENO) != STDOUT_FILENO) {
log_error_errno(errno, "Failed to dup2() fd: %m");
_exit(EXIT_FAILURE);
}
if (null_fd != STDOUT_FILENO)
null_fd = safe_close(null_fd);
stdio_unset_cloexec();
if (unshare(CLONE_NEWNET) < 0)
log_error_errno(errno, "Failed to lock tar into network namespace, ignoring: %m");
r = capability_bounding_set_drop(retain, true);
if (r < 0)
log_error_errno(r, "Failed to drop capabilities, ignoring: %m");
execlp("tar", "tar", "--numeric-owner", "-C", path, "-px", "--xattrs", "--xattrs-include=*", NULL);
log_error_errno(errno, "Failed to execute tar: %m");
_exit(EXIT_FAILURE);
}
pipefd[0] = safe_close(pipefd[0]);
r = pipefd[1];
pipefd[1] = -1;
*ret = pid;
return r;
}
