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
  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
  27 #include "libfstools/libfstools.h"
  28 #include "libfstools/volume.h"
  29
  30 static int
  31 handle_rmdir(const char *dir)
  32 {
  33         struct dirent *dt;
  34         struct stat st;
  35         DIR *d;
  36         int fd;
  37
  38         d = opendir(dir);
  39         if (!d)
  40                 return -1;
  41
  42         fd = dirfd(d);
  43
  44         while ((dt = readdir(d)) != NULL) {
  45                 if (fstatat(fd, dt->d_name, &st, AT_SYMLINK_NOFOLLOW) || S_ISDIR(st.st_mode))
  46                         continue;
  47
  48                 unlinkat(fd, dt->d_name, 0);
  49         }
  50
  51         closedir(d);
  52         rmdir(dir);
  53
  54         return 0;
  55 }
  56
  57 static int
  58 ask_user(int argc, char **argv)
  59 {
  60         if ((argc < 2) || strcmp(argv[1], "-y")) {
  61                 ULOG_WARN("This will erase all settings and remove any installed packages. Are you sure? [N/y]\n");
  62                 if (getchar() != 'y')
  63                         return -1;
  64         }
  65         return 0;
  66
  67 }
  68
  69 static int
  70 jffs2_reset(int argc, char **argv)
  71 {
  72         struct volume *v;
  73         char *mp;
  74
  75         if (ask_user(argc, argv))
  76                 return -1;
  77
  78         if (find_filesystem("overlay")) {
  79                 ULOG_ERR("overlayfs not supported by kernel\n");
  80                 return -1;
  81         }
  82
  83         v = volume_find("rootfs_data");
  84         if (!v) {
  85                 ULOG_ERR("MTD partition 'rootfs_data' not found\n");
  86                 return -1;
  87         }
  88
  89         mp = find_mount_point(v->blk, 1);
  90         if (mp) {
  91                 ULOG_INFO("%s is mounted as %s, only erasing files\n", v->blk, mp);
  92                 foreachdir(mp, handle_rmdir);
  93                 mount(mp, "/", NULL, MS_REMOUNT, 0);
  94         } else {
  95                 ULOG_INFO("%s is not mounted, erasing it\n", v->blk);
  96                 volume_erase_all(v);
  97         }
  98
  99         return 0;
 100 }
 101
 102 static int
 103 jffs2_mark(int argc, char **argv)
 104 {
 105         __u32 deadc0de = __cpu_to_be32(0xdeadc0de);
 106         struct volume *v;
 107         size_t sz;
 108         int fd;
 109
 110         if (ask_user(argc, argv))
 111                 return -1;
 112
 113         v = volume_find("rootfs_data");
 114         if (!v) {
 115                 ULOG_ERR("MTD partition 'rootfs_data' not found\n");
 116                 return -1;
 117         }
 118
 119         fd = open(v->blk, O_WRONLY);
 120         ULOG_INFO("%s - marking with deadc0de\n", v->blk);
 121         if (!fd) {
 122                 ULOG_ERR("opening %s failed\n", v->blk);
 123                 return -1;
 124         }
 125
 126         sz = write(fd, &deadc0de, sizeof(deadc0de));
 127         close(fd);
 128
 129         if (sz != 4) {
 130                 ULOG_ERR("writing %s failed: %s\n", v->blk, strerror(errno));
 131                 return -1;
 132         }
 133
 134         return 0;
 135 }
 136
 137 int main(int argc, char **argv)
 138 {
 139         if (!strcmp(*argv, "jffs2mark"))
 140                 return jffs2_mark(argc, argv);
 141         return jffs2_reset(argc, argv);
 142 }