78026bce9c
* fs/minix.c (grub_minix_find_file): Reserve more space for `fpath' so the \0 can be stored. Use `grub_strcpy' instead of `grub_strncpy' to copy `path' into it.
623 lines
16 KiB
C
623 lines
16 KiB
C
/* minix.c - The minix filesystem, version 1 and 2. */
|
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/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2004, 2005 Free Software Foundation, Inc.
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*
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* This program is free software; you can redistribute it and/or modify
|
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* it under the terms of the GNU General Public License as published by
|
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
|
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <grub/err.h>
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#include <grub/file.h>
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#include <grub/mm.h>
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#include <grub/misc.h>
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#include <grub/disk.h>
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#include <grub/dl.h>
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#include <grub/types.h>
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#define GRUB_MINIX_MAGIC 0x137F
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#define GRUB_MINIX2_MAGIC 0x2468
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#define GRUB_MINIX_MAGIC_30 0x138F
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#define GRUB_MINIX2_MAGIC_30 0x2478
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#define GRUB_MINIX_BSIZE 1024U
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#define GRUB_MINIX_LOG2_BSIZE 1
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#define GRUB_MINIX_ROOT_INODE 1
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#define GRUB_MINIX_MAX_SYMLNK_CNT 8
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#define GRUB_MINIX_SBLOCK 2
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#define GRUB_MINIX_IFDIR 0040000U
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#define GRUB_MINIX_IFLNK 0120000U
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#define GRUB_MINIX_INODE(data,field) (data->version == 1 ? \
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data->inode. field : data->inode2. field)
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#define GRUB_MINIX_INODE_ENDIAN(data,field,bits1,bits2) (data->version == 1 ? \
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grub_le_to_cpu##bits1 (data->inode.field) : \
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grub_le_to_cpu##bits2 (data->inode2.field))
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#define GRUB_MINIX_INODE_SIZE(data) GRUB_MINIX_INODE_ENDIAN (data,size,16,32)
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#define GRUB_MINIX_INODE_MODE(data) GRUB_MINIX_INODE_ENDIAN (data,mode,16,16)
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#define GRUB_MINIX_INODE_DIR_ZONES(data,blk) GRUB_MINIX_INODE_ENDIAN \
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(data,dir_zones[blk],16,32)
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#define GRUB_MINIX_INODE_INDIR_ZONE(data) \
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GRUB_MINIX_INODE_ENDIAN (data,indir_zone,16,32)
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#define GRUB_MINIX_INODE_DINDIR_ZONE(data) \
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GRUB_MINIX_INODE_ENDIAN (data,double_indir_zone,16,32)
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#define GRUB_MINIX_INODE_BLKSZ(data) (data->version == 1 ? 2 : 4)
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#define GRUB_MINIX_LOG2_ZONESZ (GRUB_MINIX_LOG2_BSIZE \
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+ grub_le_to_cpu16 (sblock->log2_zone_size))
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#define GRUB_MINIX_ZONESZ (GRUB_MINIX_BSIZE \
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<< grub_le_to_cpu16 (sblock->log2_zone_size))
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struct grub_minix_sblock
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{
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grub_uint16_t inode_cnt;
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grub_uint16_t zone_cnt;
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grub_uint16_t inode_bmap_size;
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grub_uint16_t zone_bmap_size;
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grub_uint16_t first_data_zone;
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grub_uint16_t log2_zone_size;
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grub_uint32_t max_file_size;
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grub_uint16_t magic;
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};
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struct grub_minix_inode
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{
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grub_uint16_t mode;
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grub_uint16_t uid;
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grub_uint16_t size;
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grub_uint32_t ctime;
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grub_uint8_t gid;
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grub_uint8_t nlinks;
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grub_uint16_t dir_zones[7];
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grub_uint16_t indir_zone;
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grub_uint16_t double_indir_zone;
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};
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struct grub_minix2_inode
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{
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grub_uint16_t mode;
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grub_uint16_t nlinks;
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grub_uint16_t uid;
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grub_uint16_t gid;
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grub_uint32_t size;
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grub_uint32_t atime;
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grub_uint32_t mtime;
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grub_uint32_t ctime;
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grub_uint32_t dir_zones[7];
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grub_uint32_t indir_zone;
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grub_uint32_t double_indir_zone;
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grub_uint32_t unused;
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};
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/* Information about a "mounted" minix filesystem. */
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struct grub_minix_data
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{
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struct grub_minix_sblock sblock;
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struct grub_minix_inode inode;
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struct grub_minix2_inode inode2;
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int ino;
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int linknest;
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grub_disk_t disk;
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int version;
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int filename_size;
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};
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#ifndef GRUB_UTIL
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static grub_dl_t my_mod;
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#endif
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static grub_err_t grub_minix_find_file (struct grub_minix_data *data,
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const char *path);
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static int
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grub_minix_get_file_block (struct grub_minix_data *data, unsigned int blk)
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{
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struct grub_minix_sblock *sblock = &data->sblock;
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int indir;
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auto int grub_get_indir (int, int);
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/* Read the block pointer in ZONE, on the offset NUM. */
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int grub_get_indir (int zone, int num)
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{
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if (data->version == 1)
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{
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grub_uint16_t indir16;
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grub_disk_read (data->disk,
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zone << GRUB_MINIX_LOG2_ZONESZ,
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sizeof (grub_uint16_t) * num,
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sizeof (grub_uint16_t), (char *) &indir16);
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return grub_le_to_cpu16 (indir16);
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}
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else
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{
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grub_uint32_t indir32;
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grub_disk_read (data->disk,
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zone << GRUB_MINIX_LOG2_ZONESZ,
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sizeof (grub_uint32_t) * num,
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sizeof (grub_uint32_t), (char *) &indir32);
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return grub_le_to_cpu32 (indir32);
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}
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}
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/* Direct block. */
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if (blk < 7)
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return GRUB_MINIX_INODE_DIR_ZONES (data, blk);
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/* Indirect block. */
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blk -= 7;
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if (blk < GRUB_MINIX_ZONESZ / GRUB_MINIX_INODE_BLKSZ (data))
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{
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indir = grub_get_indir (GRUB_MINIX_INODE_INDIR_ZONE (data), blk);
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return indir;
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}
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/* Double indirect block. */
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blk -= GRUB_MINIX_ZONESZ / GRUB_MINIX_INODE_BLKSZ (data);
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if (blk < (GRUB_MINIX_ZONESZ / GRUB_MINIX_INODE_BLKSZ (data))
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* (GRUB_MINIX_ZONESZ / GRUB_MINIX_INODE_BLKSZ (data)))
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{
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indir = grub_get_indir (GRUB_MINIX_INODE_DINDIR_ZONE (data),
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blk / GRUB_MINIX_ZONESZ);
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indir = grub_get_indir (indir, blk % GRUB_MINIX_ZONESZ);
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return indir;
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}
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/* This should never happen. */
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grub_error (GRUB_ERR_OUT_OF_RANGE, "file bigger than maximum size");
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return 0;
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}
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/* Read LEN bytes from the file described by DATA starting with byte
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POS. Return the amount of read bytes in READ. */
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static grub_ssize_t
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grub_minix_read_file (struct grub_minix_data *data,
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void (*read_hook) (unsigned long sector,
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unsigned offset, unsigned length),
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int pos, unsigned int len, char *buf)
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{
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struct grub_minix_sblock *sblock = &data->sblock;
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int i;
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int blockcnt;
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/* Adjust len so it we can't read past the end of the file. */
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if (len > GRUB_MINIX_INODE_SIZE (data))
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len = GRUB_MINIX_INODE_SIZE (data);
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blockcnt = (len + pos + GRUB_MINIX_BSIZE - 1) / GRUB_MINIX_BSIZE;
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for (i = pos / GRUB_MINIX_BSIZE; i < blockcnt; i++)
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{
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int blknr;
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int blockoff = pos % GRUB_MINIX_BSIZE;
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int blockend = GRUB_MINIX_BSIZE;
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int skipfirst = 0;
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blknr = grub_minix_get_file_block (data, i);
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if (grub_errno)
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return -1;
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/* Last block. */
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if (i == blockcnt - 1)
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{
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blockend = (len + pos) % GRUB_MINIX_BSIZE;
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if (!blockend)
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blockend = GRUB_MINIX_BSIZE;
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}
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/* First block. */
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if (i == (pos / (int) GRUB_MINIX_BSIZE))
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{
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skipfirst = blockoff;
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blockend -= skipfirst;
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}
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data->disk->read_hook = read_hook;
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grub_disk_read (data->disk, blknr << GRUB_MINIX_LOG2_ZONESZ,
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skipfirst, blockend, buf);
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data->disk->read_hook = 0;
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if (grub_errno)
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return -1;
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buf += GRUB_MINIX_BSIZE - skipfirst;
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}
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return len;
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}
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/* Read inode INO from the mounted filesystem described by DATA. This
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inode is used by default now. */
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static grub_err_t
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grub_minix_read_inode (struct grub_minix_data *data, int ino)
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{
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struct grub_minix_sblock *sblock = &data->sblock;
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/* Block in which the inode is stored. */
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int block;
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data->ino = ino;
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/* The first inode in minix is inode 1. */
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ino--;
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block = ((2 + grub_le_to_cpu16 (sblock->inode_bmap_size)
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+ grub_le_to_cpu16 (sblock->zone_bmap_size))
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<< GRUB_MINIX_LOG2_BSIZE);
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if (data->version == 1)
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{
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block += ino / (GRUB_DISK_SECTOR_SIZE / sizeof (struct grub_minix_inode));
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int offs = (ino % (GRUB_DISK_SECTOR_SIZE
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/ sizeof (struct grub_minix_inode))
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* sizeof (struct grub_minix_inode));
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grub_disk_read (data->disk, block, offs,
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sizeof (struct grub_minix_inode), (char *) &data->inode);
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}
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else
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{
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block += ino / (GRUB_DISK_SECTOR_SIZE
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/ sizeof (struct grub_minix2_inode));
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int offs = (ino
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% (GRUB_DISK_SECTOR_SIZE / sizeof (struct grub_minix2_inode))
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* sizeof (struct grub_minix2_inode));
|
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|
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grub_disk_read (data->disk, block, offs,
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sizeof (struct grub_minix2_inode),(char *) &data->inode2);
|
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}
|
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return GRUB_ERR_NONE;
|
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}
|
||
|
||
|
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/* Lookup the symlink the current inode points to. INO is the inode
|
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number of the directory the symlink is relative to. */
|
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static grub_err_t
|
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grub_minix_lookup_symlink (struct grub_minix_data *data, int ino)
|
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{
|
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char symlink[GRUB_MINIX_INODE_SIZE (data) + 1];
|
||
|
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if (++data->linknest > GRUB_MINIX_MAX_SYMLNK_CNT)
|
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return grub_error (GRUB_ERR_SYMLINK_LOOP, "too deep nesting of symlinks");
|
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|
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if (grub_minix_read_file (data, 0, 0,
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GRUB_MINIX_INODE_SIZE (data), symlink) < 0)
|
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return grub_errno;
|
||
|
||
symlink[GRUB_MINIX_INODE_SIZE (data)] = '\0';
|
||
|
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/* 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, "Can not 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),(char *) &data->sblock);
|
||
|
||
if (grub_le_to_cpu16 (data->sblock.magic) == GRUB_MINIX_MAGIC)
|
||
{
|
||
data->version = 1;
|
||
data->filename_size = 14;
|
||
}
|
||
else if (grub_le_to_cpu16 (data->sblock.magic) == GRUB_MINIX2_MAGIC)
|
||
{
|
||
data->version = 2;
|
||
data->filename_size = 14;
|
||
}
|
||
else if (grub_le_to_cpu16 (data->sblock.magic) == GRUB_MINIX_MAGIC_30)
|
||
{
|
||
data->version = 1;
|
||
data->filename_size = 30;
|
||
}
|
||
else if (grub_le_to_cpu16 (data->sblock.magic) == GRUB_MINIX2_MAGIC_30)
|
||
{
|
||
data->version = 2;
|
||
data->filename_size = 30;
|
||
}
|
||
else
|
||
{
|
||
grub_free (data);
|
||
grub_error (GRUB_ERR_BAD_FS, "not an minix filesystem");
|
||
return 0;
|
||
}
|
||
|
||
data->disk = disk;
|
||
data->linknest = 0;
|
||
|
||
return data;
|
||
}
|
||
|
||
static grub_err_t
|
||
grub_minix_dir (grub_device_t device, const char *path,
|
||
int (*hook) (const char *filename, int dir))
|
||
{
|
||
struct grub_minix_data *data = 0;
|
||
struct grub_minix_sblock *sblock;
|
||
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;
|
||
|
||
sblock = &data->sblock;
|
||
|
||
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;
|
||
|
||
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));
|
||
if (hook (filename, ((GRUB_MINIX_INODE_MODE (data)
|
||
& GRUB_MINIX_IFDIR) == GRUB_MINIX_IFDIR)) ? 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_ssize_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 grub_err_t
|
||
grub_minix_label (grub_device_t device __attribute ((unused)),
|
||
char **label __attribute ((unused)))
|
||
{
|
||
return GRUB_ERR_NONE;
|
||
}
|
||
|
||
|
||
static struct grub_fs grub_minix_fs =
|
||
{
|
||
.name = "minix",
|
||
.dir = grub_minix_dir,
|
||
.open = grub_minix_open,
|
||
.read = grub_minix_read,
|
||
.close = grub_minix_close,
|
||
.label = grub_minix_label,
|
||
.next = 0
|
||
};
|
||
|
||
#ifdef GRUB_UTIL
|
||
void
|
||
grub_minix_init (void)
|
||
{
|
||
grub_fs_register (&grub_minix_fs);
|
||
}
|
||
|
||
void
|
||
grub_minix_fini (void)
|
||
{
|
||
grub_fs_unregister (&grub_minix_fs);
|
||
}
|
||
#else /* ! GRUB_UTIL */
|
||
GRUB_MOD_INIT
|
||
{
|
||
grub_fs_register (&grub_minix_fs);
|
||
my_mod = mod;
|
||
}
|
||
|
||
GRUB_MOD_FINI
|
||
{
|
||
grub_fs_unregister (&grub_minix_fs);
|
||
}
|
||
#endif /* ! GRUB_UTIL */
|