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-rw-r--r--grub-core/fs/minix.c590
1 files changed, 590 insertions, 0 deletions
diff --git a/grub-core/fs/minix.c b/grub-core/fs/minix.c
new file mode 100644
index 0000000..523e6e6
--- /dev/null
+++ b/grub-core/fs/minix.c
@@ -0,0 +1,590 @@
+/* minix.c - The minix filesystem, version 1 and 2. */
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2004,2005,2006,2007,2008 Free Software Foundation, Inc.
+ *
+ * GRUB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/err.h>
+#include <grub/file.h>
+#include <grub/mm.h>
+#include <grub/misc.h>
+#include <grub/disk.h>
+#include <grub/dl.h>
+#include <grub/types.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+#ifdef MODE_MINIX2
+#define GRUB_MINIX_MAGIC 0x2468
+#define GRUB_MINIX_MAGIC_30 0x2478
+#else
+#define GRUB_MINIX_MAGIC 0x137F
+#define GRUB_MINIX_MAGIC_30 0x138F
+#endif
+#define GRUB_MINIX_BSIZE 1024U
+#define GRUB_MINIX_LOG2_BSIZE 1
+#define GRUB_MINIX_ROOT_INODE 1
+#define GRUB_MINIX_MAX_SYMLNK_CNT 8
+#define GRUB_MINIX_SBLOCK 2
+
+#define GRUB_MINIX_IFDIR 0040000U
+#define GRUB_MINIX_IFLNK 0120000U
+
+#ifdef MODE_MINIX2
+typedef grub_uint32_t grub_minix_uintn_t;
+#define grub_minix_le_to_cpu_n grub_le_to_cpu32
+#else
+typedef grub_uint16_t grub_minix_uintn_t;
+#define grub_minix_le_to_cpu_n grub_le_to_cpu16
+#endif
+
+#define GRUB_MINIX_INODE_BLKSZ(data) sizeof (grub_minix_uintn_t)
+
+#define GRUB_MINIX_INODE_SIZE(data) (grub_minix_le_to_cpu_n (data->inode.size))
+#define GRUB_MINIX_INODE_MODE(data) (grub_le_to_cpu16 (data->inode.mode))
+#define GRUB_MINIX_INODE_DIR_ZONES(data,blk) (grub_minix_le_to_cpu_n \
+ (data->inode.dir_zones[blk]))
+#define GRUB_MINIX_INODE_INDIR_ZONE(data) (grub_minix_le_to_cpu_n \
+ (data->inode.indir_zone))
+#define GRUB_MINIX_INODE_DINDIR_ZONE(data) (grub_minix_le_to_cpu_n \
+ (data->inode.double_indir_zone))
+
+#define GRUB_MINIX_LOG2_ZONESZ (GRUB_MINIX_LOG2_BSIZE \
+ + grub_le_to_cpu16 (sblock->log2_zone_size))
+#define GRUB_MINIX_ZONESZ (GRUB_MINIX_BSIZE \
+ << grub_le_to_cpu16 (sblock->log2_zone_size))
+
+struct grub_minix_sblock
+{
+ grub_uint16_t inode_cnt;
+ grub_uint16_t zone_cnt;
+ grub_uint16_t inode_bmap_size;
+ grub_uint16_t zone_bmap_size;
+ grub_uint16_t first_data_zone;
+ grub_uint16_t log2_zone_size;
+ grub_uint32_t max_file_size;
+ grub_uint16_t magic;
+};
+
+#ifndef MODE_MINIX2
+struct grub_minix_inode
+{
+ grub_uint16_t mode;
+ grub_uint16_t uid;
+ grub_uint16_t size;
+ grub_uint32_t ctime;
+ grub_uint8_t gid;
+ grub_uint8_t nlinks;
+ grub_uint16_t dir_zones[7];
+ grub_uint16_t indir_zone;
+ grub_uint16_t double_indir_zone;
+};
+
+#else
+
+struct grub_minix_inode
+{
+ grub_uint16_t mode;
+ grub_uint16_t nlinks;
+ grub_uint16_t uid;
+ grub_uint16_t gid;
+ grub_uint32_t size;
+ grub_uint32_t atime;
+ grub_uint32_t mtime;
+ grub_uint32_t ctime;
+ grub_uint32_t dir_zones[7];
+ grub_uint32_t indir_zone;
+ grub_uint32_t double_indir_zone;
+ grub_uint32_t unused;
+
+};
+
+#endif
+
+/* Information about a "mounted" minix filesystem. */
+struct grub_minix_data
+{
+ struct grub_minix_sblock sblock;
+ struct grub_minix_inode inode;
+ int ino;
+ int linknest;
+ grub_disk_t disk;
+ int filename_size;
+};
+
+static grub_dl_t my_mod;
+
+static grub_err_t grub_minix_find_file (struct grub_minix_data *data,
+ const char *path);
+
+static int
+grub_minix_get_file_block (struct grub_minix_data *data, unsigned int blk)
+{
+ struct grub_minix_sblock *sblock = &data->sblock;
+ int indir;
+
+ auto int grub_get_indir (int, int);
+
+ /* Read the block pointer in ZONE, on the offset NUM. */
+ int grub_get_indir (int zone, int num)
+ {
+ grub_minix_uintn_t indirn;
+ grub_disk_read (data->disk,
+ zone << GRUB_MINIX_LOG2_ZONESZ,
+ sizeof (grub_minix_uintn_t) * num,
+ sizeof (grub_minix_uintn_t), (char *) &indirn);
+ return grub_minix_le_to_cpu_n (indirn);
+ }
+
+ /* Direct block. */
+ if (blk < 7)
+ return GRUB_MINIX_INODE_DIR_ZONES (data, blk);
+
+ /* Indirect block. */
+ blk -= 7;
+ if (blk < GRUB_MINIX_ZONESZ / GRUB_MINIX_INODE_BLKSZ (data))
+ {
+ indir = grub_get_indir (GRUB_MINIX_INODE_INDIR_ZONE (data), blk);
+ return indir;
+ }
+
+ /* Double indirect block. */
+ blk -= GRUB_MINIX_ZONESZ / GRUB_MINIX_INODE_BLKSZ (data);
+ if (blk < (GRUB_MINIX_ZONESZ / GRUB_MINIX_INODE_BLKSZ (data))
+ * (GRUB_MINIX_ZONESZ / GRUB_MINIX_INODE_BLKSZ (data)))
+ {
+ indir = grub_get_indir (GRUB_MINIX_INODE_DINDIR_ZONE (data),
+ blk / GRUB_MINIX_ZONESZ);
+
+ indir = grub_get_indir (indir, blk % GRUB_MINIX_ZONESZ);
+
+ return indir;
+ }
+
+ /* This should never happen. */
+ grub_error (GRUB_ERR_OUT_OF_RANGE, "file bigger than maximum size");
+
+ return 0;
+}
+
+
+/* Read LEN bytes from the file described by DATA starting with byte
+ POS. Return the amount of read bytes in READ. */
+static grub_ssize_t
+grub_minix_read_file (struct grub_minix_data *data,
+ void NESTED_FUNC_ATTR (*read_hook) (grub_disk_addr_t sector,
+ unsigned offset, unsigned length),
+ int pos, grub_disk_addr_t len, char *buf)
+{
+ struct grub_minix_sblock *sblock = &data->sblock;
+ int i;
+ int blockcnt;
+
+ /* Adjust len so it we can't read past the end of the file. */
+ if (len + pos > GRUB_MINIX_INODE_SIZE (data))
+ len = GRUB_MINIX_INODE_SIZE (data) - pos;
+
+ blockcnt = (len + pos + GRUB_MINIX_BSIZE - 1) / GRUB_MINIX_BSIZE;
+
+ for (i = pos / GRUB_MINIX_BSIZE; i < blockcnt; i++)
+ {
+ int blknr;
+ int blockoff = pos % GRUB_MINIX_BSIZE;
+ int blockend = GRUB_MINIX_BSIZE;
+
+ int skipfirst = 0;
+
+ blknr = grub_minix_get_file_block (data, i);
+ if (grub_errno)
+ return -1;
+
+ /* Last block. */
+ if (i == blockcnt - 1)
+ {
+ blockend = (len + pos) % GRUB_MINIX_BSIZE;
+
+ if (!blockend)
+ blockend = GRUB_MINIX_BSIZE;
+ }
+
+ /* First block. */
+ if (i == (pos / (int) GRUB_MINIX_BSIZE))
+ {
+ skipfirst = blockoff;
+ blockend -= skipfirst;
+ }
+
+ data->disk->read_hook = read_hook;
+ grub_disk_read (data->disk, blknr << GRUB_MINIX_LOG2_ZONESZ,
+ skipfirst, blockend, buf);
+
+ data->disk->read_hook = 0;
+ if (grub_errno)
+ return -1;
+
+ buf += GRUB_MINIX_BSIZE - skipfirst;
+ }
+
+ return len;
+}
+
+
+/* Read inode INO from the mounted filesystem described by DATA. This
+ inode is used by default now. */
+static grub_err_t
+grub_minix_read_inode (struct grub_minix_data *data, int ino)
+{
+ struct grub_minix_sblock *sblock = &data->sblock;
+
+ /* Block in which the inode is stored. */
+ int block;
+ data->ino = ino;
+
+ /* The first inode in minix is inode 1. */
+ ino--;
+
+ block = ((2 + grub_le_to_cpu16 (sblock->inode_bmap_size)
+ + grub_le_to_cpu16 (sblock->zone_bmap_size))
+ << GRUB_MINIX_LOG2_BSIZE);
+
+ block += ino / (GRUB_DISK_SECTOR_SIZE / sizeof (struct grub_minix_inode));
+ int offs = (ino % (GRUB_DISK_SECTOR_SIZE
+ / sizeof (struct grub_minix_inode))
+ * sizeof (struct grub_minix_inode));
+
+ grub_disk_read (data->disk, block, offs,
+ sizeof (struct grub_minix_inode), &data->inode);
+
+ return GRUB_ERR_NONE;
+}
+
+
+/* Lookup the symlink the current inode points to. INO is the inode
+ number of the directory the symlink is relative to. */
+static grub_err_t
+grub_minix_lookup_symlink (struct grub_minix_data *data, int ino)
+{
+ char symlink[GRUB_MINIX_INODE_SIZE (data) + 1];
+
+ if (++data->linknest > GRUB_MINIX_MAX_SYMLNK_CNT)
+ return grub_error (GRUB_ERR_SYMLINK_LOOP, "too deep nesting of symlinks");
+
+ if (grub_minix_read_file (data, 0, 0,
+ GRUB_MINIX_INODE_SIZE (data), symlink) < 0)
+ return grub_errno;
+
+ symlink[GRUB_MINIX_INODE_SIZE (data)] = '\0';
+
+ /* The symlink is an absolute path, go back to the root inode. */
+ if (symlink[0] == '/')
+ ino = GRUB_MINIX_ROOT_INODE;
+
+ /* Now load in the old inode. */
+ if (grub_minix_read_inode (data, ino))
+ return grub_errno;
+
+ grub_minix_find_file (data, symlink);
+ if (grub_errno)
+ grub_error (grub_errno, "cannot follow symlink `%s'", symlink);
+
+ return grub_errno;
+}
+
+
+/* Find the file with the pathname PATH on the filesystem described by
+ DATA. */
+static grub_err_t
+grub_minix_find_file (struct grub_minix_data *data, const char *path)
+{
+ char fpath[grub_strlen (path) + 1];
+ char *name = fpath;
+ char *next;
+ unsigned int pos = 0;
+ int dirino;
+
+ grub_strcpy (fpath, path);
+
+ /* Skip the first slash. */
+ if (name[0] == '/')
+ {
+ name++;
+ if (!*name)
+ return 0;
+ }
+
+ /* Extract the actual part from the pathname. */
+ next = grub_strchr (name, '/');
+ if (next)
+ {
+ next[0] = '\0';
+ next++;
+ }
+
+ do
+ {
+ grub_uint16_t ino;
+ char filename[data->filename_size + 1];
+
+ if (grub_strlen (name) == 0)
+ return GRUB_ERR_NONE;
+
+ if (grub_minix_read_file (data, 0, pos, sizeof (ino),
+ (char *) &ino) < 0)
+ return grub_errno;
+ if (grub_minix_read_file (data, 0, pos + sizeof (ino),
+ data->filename_size, (char *) filename)< 0)
+ return grub_errno;
+
+ filename[data->filename_size] = '\0';
+
+ /* Check if the current direntry matches the current part of the
+ pathname. */
+ if (!grub_strcmp (name, filename))
+ {
+ dirino = data->ino;
+ grub_minix_read_inode (data, grub_le_to_cpu16 (ino));
+
+ /* Follow the symlink. */
+ if ((GRUB_MINIX_INODE_MODE (data)
+ & GRUB_MINIX_IFLNK) == GRUB_MINIX_IFLNK)
+ {
+ grub_minix_lookup_symlink (data, dirino);
+ if (grub_errno)
+ return grub_errno;
+ }
+
+ if (!next)
+ return 0;
+
+ pos = 0;
+
+ name = next;
+ next = grub_strchr (name, '/');
+ if (next)
+ {
+ next[0] = '\0';
+ next++;
+ }
+
+ if ((GRUB_MINIX_INODE_MODE (data)
+ & GRUB_MINIX_IFDIR) != GRUB_MINIX_IFDIR)
+ return grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a directory");
+
+ continue;
+ }
+
+ pos += sizeof (ino) + data->filename_size;
+ } while (pos < GRUB_MINIX_INODE_SIZE (data));
+
+ grub_error (GRUB_ERR_FILE_NOT_FOUND, "file not found");
+ return grub_errno;
+}
+
+
+/* Mount the filesystem on the disk DISK. */
+static struct grub_minix_data *
+grub_minix_mount (grub_disk_t disk)
+{
+ struct grub_minix_data *data;
+
+ data = grub_malloc (sizeof (struct grub_minix_data));
+ if (!data)
+ return 0;
+
+ /* Read the superblock. */
+ grub_disk_read (disk, GRUB_MINIX_SBLOCK, 0,
+ sizeof (struct grub_minix_sblock),&data->sblock);
+ if (grub_errno)
+ goto fail;
+
+ if (grub_le_to_cpu16 (data->sblock.magic) == GRUB_MINIX_MAGIC)
+ data->filename_size = 14;
+ else if (grub_le_to_cpu16 (data->sblock.magic) == GRUB_MINIX_MAGIC_30)
+ data->filename_size = 30;
+ else
+ goto fail;
+
+ data->disk = disk;
+ data->linknest = 0;
+
+ return data;
+
+ fail:
+ grub_free (data);
+#ifdef MODE_MINIX2
+ grub_error (GRUB_ERR_BAD_FS, "not a minix2 filesystem");
+#else
+ grub_error (GRUB_ERR_BAD_FS, "not a minix filesystem");
+#endif
+ return 0;
+}
+
+static grub_err_t
+grub_minix_dir (grub_device_t device, const char *path,
+ int (*hook) (const char *filename,
+ const struct grub_dirhook_info *info))
+{
+ struct grub_minix_data *data = 0;
+ unsigned int pos = 0;
+
+ data = grub_minix_mount (device->disk);
+ if (!data)
+ return grub_errno;
+
+ grub_minix_read_inode (data, GRUB_MINIX_ROOT_INODE);
+ if (grub_errno)
+ goto fail;
+
+ grub_minix_find_file (data, path);
+ if (grub_errno)
+ goto fail;
+
+ if ((GRUB_MINIX_INODE_MODE (data) & GRUB_MINIX_IFDIR) != GRUB_MINIX_IFDIR)
+ {
+ grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a directory");
+ goto fail;
+ }
+
+ while (pos < GRUB_MINIX_INODE_SIZE (data))
+ {
+ grub_uint16_t ino;
+ char filename[data->filename_size + 1];
+ int dirino = data->ino;
+ struct grub_dirhook_info info;
+ grub_memset (&info, 0, sizeof (info));
+
+
+ if (grub_minix_read_file (data, 0, pos, sizeof (ino),
+ (char *) &ino) < 0)
+ return grub_errno;
+
+ if (grub_minix_read_file (data, 0, pos + sizeof (ino),
+ data->filename_size,
+ (char *) filename) < 0)
+ return grub_errno;
+ filename[data->filename_size] = '\0';
+
+ /* The filetype is not stored in the dirent. Read the inode to
+ find out the filetype. This *REALLY* sucks. */
+ grub_minix_read_inode (data, grub_le_to_cpu16 (ino));
+ info.dir = ((GRUB_MINIX_INODE_MODE (data)
+ & GRUB_MINIX_IFDIR) == GRUB_MINIX_IFDIR);
+ if (hook (filename, &info) ? 1 : 0)
+ break;
+
+ /* Load the old inode back in. */
+ grub_minix_read_inode (data, dirino);
+
+ pos += sizeof (ino) + data->filename_size;
+ }
+
+ fail:
+ grub_free (data);
+ return grub_errno;
+}
+
+
+/* Open a file named NAME and initialize FILE. */
+static grub_err_t
+grub_minix_open (struct grub_file *file, const char *name)
+{
+ struct grub_minix_data *data;
+ data = grub_minix_mount (file->device->disk);
+ if (!data)
+ return grub_errno;
+
+ /* Open the inode op the root directory. */
+ grub_minix_read_inode (data, GRUB_MINIX_ROOT_INODE);
+ if (grub_errno)
+ {
+ grub_free (data);
+ return grub_errno;
+ }
+
+ if (!name || name[0] != '/')
+ {
+ grub_error (GRUB_ERR_BAD_FILENAME, "bad filename");
+ return grub_errno;
+ }
+
+ /* Traverse the directory tree to the node that should be
+ opened. */
+ grub_minix_find_file (data, name);
+ if (grub_errno)
+ {
+ grub_free (data);
+ return grub_errno;
+ }
+
+ file->data = data;
+ file->size = GRUB_MINIX_INODE_SIZE (data);
+
+ return GRUB_ERR_NONE;
+}
+
+
+static grub_ssize_t
+grub_minix_read (grub_file_t file, char *buf, grub_size_t len)
+{
+ struct grub_minix_data *data =
+ (struct grub_minix_data *) file->data;
+
+ return grub_minix_read_file (data, file->read_hook, file->offset, len, buf);
+}
+
+
+static grub_err_t
+grub_minix_close (grub_file_t file)
+{
+ grub_free (file->data);
+
+ return GRUB_ERR_NONE;
+}
+
+
+
+static struct grub_fs grub_minix_fs =
+ {
+#ifdef MODE_MINIX2
+ .name = "minix2",
+#else
+ .name = "minix",
+#endif
+ .dir = grub_minix_dir,
+ .open = grub_minix_open,
+ .read = grub_minix_read,
+ .close = grub_minix_close,
+ .next = 0
+ };
+
+#ifdef MODE_MINIX2
+GRUB_MOD_INIT(minix2)
+#else
+GRUB_MOD_INIT(minix)
+#endif
+{
+ grub_fs_register (&grub_minix_fs);
+ my_mod = mod;
+}
+
+#ifdef MODE_MINIX2
+GRUB_MOD_FINI(minix2)
+#else
+GRUB_MOD_FINI(minix)
+#endif
+{
+ grub_fs_unregister (&grub_minix_fs);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-21 05:25:57 +0000