root/tools/testing/selftests/wireguard/qemu/init.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
 */

#define _GNU_SOURCE
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <fcntl.h>
#include <time.h>
#include <sys/wait.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/io.h>
#include <sys/ioctl.h>
#include <sys/reboot.h>
#include <sys/utsname.h>
#include <sys/sendfile.h>
#include <sys/sysmacros.h>
#include <sys/random.h>
#include <linux/random.h>
#include <linux/version.h>

__attribute__((noreturn)) static void poweroff(void)
{
        fflush(stdout);
        fflush(stderr);
        reboot(RB_AUTOBOOT);
        sleep(30);
        fprintf(stderr, "\x1b[37m\x1b[41m\x1b[1mFailed to power off!!!\x1b[0m\n");
        exit(1);
}

static void panic(const char *what)
{
        fprintf(stderr, "\n\n\x1b[37m\x1b[41m\x1b[1mSOMETHING WENT HORRIBLY WRONG\x1b[0m\n\n    \x1b[31m\x1b[1m%s: %s\x1b[0m\n\n\x1b[37m\x1b[44m\x1b[1mPower off...\x1b[0m\n\n", what, strerror(errno));
        poweroff();
}

#define pretty_message(msg) puts("\x1b[32m\x1b[1m" msg "\x1b[0m")

static void print_banner(void)
{
        struct utsname utsname;
        int len;

        if (uname(&utsname) < 0)
                panic("uname");

        len = strlen("    WireGuard Test Suite on       ") + strlen(utsname.sysname) + strlen(utsname.release) + strlen(utsname.machine);
        printf("\x1b[45m\x1b[33m\x1b[1m%*.s\x1b[0m\n\x1b[45m\x1b[33m\x1b[1m    WireGuard Test Suite on %s %s %s    \x1b[0m\n\x1b[45m\x1b[33m\x1b[1m%*.s\x1b[0m\n\n", len, "", utsname.sysname, utsname.release, utsname.machine, len, "");
}

static void seed_rng(void)
{
        int bits = 256, fd;

        if (!getrandom(NULL, 0, GRND_NONBLOCK))
                return;
        pretty_message("[+] Fake seeding RNG...");
        fd = open("/dev/random", O_WRONLY);
        if (fd < 0)
                panic("open(random)");
        if (ioctl(fd, RNDADDTOENTCNT, &bits) < 0)
                panic("ioctl(RNDADDTOENTCNT)");
        close(fd);
}

static void set_time(void)
{
        if (time(NULL))
                return;
        pretty_message("[+] Setting fake time...");
        if (stime(&(time_t){1433512680}) < 0)
                panic("settimeofday()");
}

static void mount_filesystems(void)
{
        pretty_message("[+] Mounting filesystems...");
        mkdir("/dev", 0755);
        mkdir("/proc", 0755);
        mkdir("/sys", 0755);
        mkdir("/tmp", 0755);
        mkdir("/run", 0755);
        mkdir("/var", 0755);
        if (mount("none", "/dev", "devtmpfs", 0, NULL))
                panic("devtmpfs mount");
        if (mount("none", "/proc", "proc", 0, NULL))
                panic("procfs mount");
        if (mount("none", "/sys", "sysfs", 0, NULL))
                panic("sysfs mount");
        if (mount("none", "/tmp", "tmpfs", 0, NULL))
                panic("tmpfs mount");
        if (mount("none", "/run", "tmpfs", 0, NULL))
                panic("tmpfs mount");
        if (mount("none", "/sys/kernel/debug", "debugfs", 0, NULL))
                ; /* Not a problem if it fails.*/
        if (symlink("/run", "/var/run"))
                panic("run symlink");
        if (symlink("/proc/self/fd", "/dev/fd"))
                panic("fd symlink");
}

static void enable_logging(void)
{
        int fd;
        pretty_message("[+] Enabling logging...");
        fd = open("/proc/sys/kernel/printk", O_WRONLY);
        if (fd >= 0) {
                if (write(fd, "9\n", 2) != 2)
                        panic("write(printk)");
                close(fd);
        }
        fd = open("/proc/sys/debug/exception-trace", O_WRONLY);
        if (fd >= 0) {
                if (write(fd, "1\n", 2) != 2)
                        panic("write(exception-trace)");
                close(fd);
        }
}

static void kmod_selftests(void)
{
        FILE *file;
        char line[2048], *start, *pass;
        bool success = true;
        pretty_message("[+] Module self-tests:");
        file = fopen("/proc/kmsg", "r");
        if (!file)
                panic("fopen(kmsg)");
        if (fcntl(fileno(file), F_SETFL, O_NONBLOCK) < 0)
                panic("fcntl(kmsg, nonblock)");
        while (fgets(line, sizeof(line), file)) {
                start = strstr(line, "wireguard: ");
                if (!start)
                        continue;
                start += 11;
                *strchrnul(start, '\n') = '\0';
                if (strstr(start, "www.wireguard.com"))
                        break;
                pass = strstr(start, ": pass");
                if (!pass || pass[6] != '\0') {
                        success = false;
                        printf(" \x1b[31m*  %s\x1b[0m\n", start);
                } else
                        printf(" \x1b[32m*  %s\x1b[0m\n", start);
        }
        fclose(file);
        if (!success) {
                puts("\x1b[31m\x1b[1m[-] Tests failed! \u2639\x1b[0m");
                poweroff();
        }
}

static void launch_tests(void)
{
        char cmdline[4096], *success_dev;
        int status, fd;
        pid_t pid;

        pretty_message("[+] Launching tests...");
        pid = fork();
        if (pid == -1)
                panic("fork");
        else if (pid == 0) {
                execl("/init.sh", "init", NULL);
                panic("exec");
        }
        if (waitpid(pid, &status, 0) < 0)
                panic("waitpid");
        if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
                pretty_message("[+] Tests successful! :-)");
                fd = open("/proc/cmdline", O_RDONLY);
                if (fd < 0)
                        panic("open(/proc/cmdline)");
                if (read(fd, cmdline, sizeof(cmdline) - 1) <= 0)
                        panic("read(/proc/cmdline)");
                cmdline[sizeof(cmdline) - 1] = '\0';
                for (success_dev = strtok(cmdline, " \n"); success_dev; success_dev = strtok(NULL, " \n")) {
                        if (strncmp(success_dev, "wg.success=", 11))
                                continue;
                        memcpy(success_dev + 11 - 5, "/dev/", 5);
                        success_dev += 11 - 5;
                        break;
                }
                if (!success_dev || !strlen(success_dev))
                        panic("Unable to find success device");

                fd = open(success_dev, O_WRONLY);
                if (fd < 0)
                        panic("open(success_dev)");
                if (write(fd, "success\n", 8) != 8)
                        panic("write(success_dev)");
                close(fd);
        } else {
                const char *why = "unknown cause";
                int what = -1;

                if (WIFEXITED(status)) {
                        why = "exit code";
                        what = WEXITSTATUS(status);
                } else if (WIFSIGNALED(status)) {
                        why = "signal";
                        what = WTERMSIG(status);
                }
                printf("\x1b[31m\x1b[1m[-] Tests failed with %s %d! \u2639\x1b[0m\n", why, what);
        }
}

static void ensure_console(void)
{
        for (unsigned int i = 0; i < 1000; ++i) {
                int fd = open("/dev/console", O_RDWR);
                if (fd < 0) {
                        usleep(50000);
                        continue;
                }
                dup2(fd, 0);
                dup2(fd, 1);
                dup2(fd, 2);
                close(fd);
                if (write(1, "\0\0\0\0\n", 5) == 5)
                        return;
        }
        panic("Unable to open console device");
}

static void clear_leaks(void)
{
        int fd;

        fd = open("/sys/kernel/debug/kmemleak", O_WRONLY);
        if (fd < 0)
                return;
        pretty_message("[+] Starting memory leak detection...");
        write(fd, "clear\n", 5);
        close(fd);
}

static void check_leaks(void)
{
        int fd;

        fd = open("/sys/kernel/debug/kmemleak", O_WRONLY);
        if (fd < 0)
                return;
        pretty_message("[+] Scanning for memory leaks...");
        sleep(2); /* Wait for any grace periods. */
        write(fd, "scan\n", 5);
        close(fd);

        fd = open("/sys/kernel/debug/kmemleak", O_RDONLY);
        if (fd < 0)
                return;
        if (sendfile(1, fd, NULL, 0x7ffff000) > 0)
                panic("Memory leaks encountered");
        close(fd);
}

int main(int argc, char *argv[])
{
        ensure_console();
        print_banner();
        mount_filesystems();
        seed_rng();
        set_time();
        kmod_selftests();
        enable_logging();
        clear_leaks();
        launch_tests();
        check_leaks();
        poweroff();
        return 1;
}