示例#1
0
文件: resolved.c 项目: OpenDZ/systemd
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;
}
示例#2
0
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;
}