jffs2reset.c

   1 /*
   2  * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU Lesser General Public License version 2.1
   6  * as published by the Free Software Foundation
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <sys/mount.h>
  15 #include <sys/types.h>
  16 #include <sys/stat.h>
  17 #include <sys/reboot.h>
  18 #include <libubox/ulog.h>
  19
  20 #include <fcntl.h>
  21 #include <dirent.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26 #include <getopt.h>
  27
  28
  29 #include "libfstools/libfstools.h"
  30 #include "libfstools/volume.h"
  31
  32 static int jffs2_mark(struct volume *v);
  33
  34 static int
  35 ask_user(void)
  36 {
  37         ULOG_WARN("This will erase all settings and remove any installed packages. Are you sure? [N/y]\n");
  38         if (getchar() != 'y')
  39                 return -1;
  40         return 0;
  41 }
  42
  43 static int jffs2_reset(struct volume *v, int reset)
  44 {
  45         char *mp;
  46
  47         mp = find_mount_point(v->blk, 1);
  48         if (mp) {
  49                 ULOG_INFO("%s is mounted as %s, only erasing files\n", v->blk, mp);
  50                 fs_state_set("/overlay", FS_STATE_PENDING);
  51                 overlay_delete(mp, false);
  52                 mount(mp, "/", NULL, MS_REMOUNT, 0);
  53         } else {
  54                 ULOG_INFO("%s is not mounted\n", v->blk);
  55                 return jffs2_mark(v);
  56         }
  57
  58         if (reset) {
  59                 sync();
  60                 sleep(2);
  61                 reboot(RB_AUTOBOOT);
  62                 while (1)
  63                         ;
  64         }
  65
  66         return 0;
  67 }
  68
  69 static int jffs2_mark(struct volume *v)
  70 {
  71         __u32 deadc0de = __cpu_to_be32(0xdeadc0de);
  72         size_t sz;
  73         int fd;
  74
  75         fd = open(v->blk, O_WRONLY);
  76         ULOG_INFO("%s will be erased on next mount\n", v->blk);
  77         if (!fd) {
  78                 ULOG_ERR("opening %s failed\n", v->blk);
  79                 return -1;
  80         }
  81
  82         sz = write(fd, &deadc0de, sizeof(deadc0de));
  83         close(fd);
  84
  85         if (sz != 4) {
  86                 ULOG_ERR("writing %s failed: %m\n", v->blk);
  87                 return -1;
  88         }
  89
  90         return 0;
  91 }
  92
  93 int main(int argc, char **argv)
  94 {
  95         struct volume *v;
  96         int ch, yes = 0, reset = 0;
  97         while ((ch = getopt(argc, argv, "yr")) != -1) {
  98                 switch(ch) {
  99                 case 'y':
 100                         yes = 1;
 101                         break;
 102                 case 'r':
 103                         reset = 1;
 104                         break;
 105                 }
 106
 107         }
 108
 109         if (!yes && ask_user())
 110                 return -1;
 111
 112         /*
 113          * TODO: Currently this only checks if kernel supports OverlayFS. We
 114          * should check if there is a mount point using it with rootfs_data
 115          * as upperdir.
 116          */
 117         if (find_filesystem("overlay")) {
 118                 ULOG_ERR("overlayfs not supported by kernel\n");
 119                 return -1;
 120         }
 121
 122         v = volume_find("rootfs_data");
 123         if (!v) {
 124                 ULOG_ERR("MTD partition 'rootfs_data' not found\n");
 125                 return -1;
 126         }
 127
 128         volume_init(v);
 129         if (!strcmp(*argv, "jffs2mark"))
 130                 return jffs2_mark(v);
 131         return jffs2_reset(v, reset);
 132 }