upgraded/upgraded.c

   1 /*
   2  * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   3  * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #define _GNU_SOURCE
  16
  17 #include <sys/reboot.h>
  18
  19 #include <fcntl.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <errno.h>
  25
  26 #include <libubox/uloop.h>
  27
  28 #include "../watchdog.h"
  29
  30 #ifndef O_PATH
  31 #define O_PATH          010000000
  32 #endif
  33
  34 static struct uloop_process upgrade_proc;
  35 unsigned int debug = 2;
  36
  37 static void upgrade_proc_cb(struct uloop_process *proc, int ret)
  38 {
  39         if (ret)
  40                 fprintf(stderr, "sysupgrade aborted with return code: %d\n", ret);
  41         uloop_end();
  42 }
  43
  44 static void sysupgrade(char *path, char *command)
  45 {
  46         char *args[] = { "/lib/upgrade/stage2", path, command, NULL };
  47
  48         upgrade_proc.cb = upgrade_proc_cb;
  49         upgrade_proc.pid = fork();
  50         if (upgrade_proc.pid < 0) {
  51                 fprintf(stderr, "Failed to fork sysupgrade\n");
  52                 return;
  53         }
  54
  55         if (!upgrade_proc.pid) {
  56                 /* Child */
  57                 execvp(args[0], args);
  58                 fprintf(stderr, "Failed to exec sysupgrade\n");
  59                 _exit(-1);
  60         }
  61
  62         uloop_process_add(&upgrade_proc);
  63         uloop_run();
  64 }
  65
  66 int main(int argc, char **argv)
  67 {
  68         pid_t p = getpid();
  69
  70         if (p != 1) {
  71                 fprintf(stderr, "this tool needs to run as pid 1\n");
  72                 return 1;
  73         }
  74
  75         int fd = open("/", O_DIRECTORY|O_PATH);
  76         if (fd < 0) {
  77                 fprintf(stderr, "unable to open prefix directory: %m\n");
  78                 return 1;
  79         }
  80
  81         if (chroot(".") < 0) {
  82                 fprintf(stderr, "failed to chroot: %m\n");
  83                 return 1;
  84         }
  85
  86         if (fchdir(fd) == -1) {
  87                 fprintf(stderr, "failed to chdir to prefix directory: %m\n");
  88                 return 1;
  89         }
  90         close(fd);
  91
  92         if (argc != 3) {
  93                 fprintf(stderr, "sysupgrade stage 2 failed, invalid command line\n");
  94                 return 1;
  95         }
  96
  97         uloop_init();
  98         watchdog_init(0);
  99         sysupgrade(argv[1], argv[2]);
 100
 101         reboot(RB_AUTOBOOT);
 102
 103         return 0;
 104 }