461 lines
11 KiB
C
461 lines
11 KiB
C
/* squash4.c - SquashFS */
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/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2010 Free Software Foundation, Inc.
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*
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* GRUB 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 3 of the License, or
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* (at your option) any later version.
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*
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* GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>.
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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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#include <grub/fshelp.h>
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#include <grub/deflate.h>
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/*
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object format Pointed by
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superblock RAW Fixed offset (0)
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data RAW ? Fixed offset (60)
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inode table Chunk superblock
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dir table Chunk superblock
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fragment table Chunk unk1
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unk1 RAW, Chunk superblock
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unk2 RAW superblock
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UID/GID Chunk exttblptr
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exttblptr RAW superblock
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UID/GID table is the array ot uint32_t
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unk1 contains pointer to unk3 followed by some chunk.
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unk2 containts one uint64_t
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*/
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struct grub_squash_super
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{
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grub_uint32_t magic;
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#define SQUASH_MAGIC 0x73717368
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grub_uint32_t dummy1;
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grub_uint32_t creation_time;
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grub_uint32_t dummy2;
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grub_uint32_t dummy3[4];
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grub_uint16_t root_ino_offset;
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grub_uint16_t root_ino_chunk;
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grub_uint32_t dummy4;
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grub_uint64_t total_size;
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grub_uint64_t exttbloffset;
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grub_uint32_t dummy5[2];
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grub_uint64_t inodeoffset;
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grub_uint64_t diroffset;
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grub_uint64_t unk1offset;
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grub_uint64_t unk2offset;
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};
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/* Chunk-based */
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struct grub_squash_inode
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{
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/* Same values as direlem types. */
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grub_uint16_t type;
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grub_uint16_t dummy1[3];
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grub_uint32_t mtime;
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grub_uint16_t dummy2[2];
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grub_uint32_t chunk;
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grub_uint32_t fragment;
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grub_uint32_t offset;
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grub_uint32_t size;
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} __attribute__ ((packed));
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/* Chunk-based. */
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struct grub_squash_dirent_header
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{
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/* Actually the value is the number of elements - 1. */
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grub_uint16_t nelems;
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grub_uint16_t dummy1;
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grub_uint32_t ino_chunk;
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grub_uint16_t dummy2[2];
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};
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struct grub_squash_dirent
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{
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grub_uint16_t ino_offset;
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grub_uint16_t dummy;
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grub_uint16_t type;
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#define SQUASH_TYPE_DIR 1
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#define SQUASH_TYPE_REGULAR 2
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/* Actually the value is the length of name - 1. */
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grub_uint16_t namelen;
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char name[0];
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};
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struct grub_squash_frag_desc
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{
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grub_uint64_t offset;
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grub_uint64_t dummy;
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};
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#define SQUASH_CHUNK_SIZE 0x2000
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#define SQUASH_CHUNK_FLAGS 0x8000
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#define SQUASH_CHUNK_UNCOMPRESSED 0x8000
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struct grub_squash_data
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{
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grub_disk_t disk;
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struct grub_squash_super sb;
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struct grub_squash_inode ino;
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grub_uint64_t fragments;
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};
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struct grub_fshelp_node
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{
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struct grub_squash_data *data;
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struct grub_squash_inode ino;
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};
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static grub_err_t
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read_chunk (grub_disk_t disk, void *buf, grub_size_t len,
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grub_uint64_t chunk, grub_off_t offset)
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{
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grub_uint64_t chunk_start;
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chunk_start = grub_le_to_cpu64 (chunk);
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while (len > 0)
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{
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grub_uint64_t csize;
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grub_uint16_t d;
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grub_err_t err;
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while (1)
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{
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err = grub_disk_read (disk, chunk_start >> GRUB_DISK_SECTOR_BITS,
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chunk_start & (GRUB_DISK_SECTOR_SIZE - 1),
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sizeof (d), &d);
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if (err)
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return err;
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if (offset < SQUASH_CHUNK_SIZE)
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break;
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offset -= SQUASH_CHUNK_SIZE;
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chunk_start += 2 + (grub_le_to_cpu16 (d) & ~SQUASH_CHUNK_FLAGS);
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}
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csize = SQUASH_CHUNK_SIZE - offset;
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if (csize > len)
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csize = len;
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if (grub_le_to_cpu16 (d) & SQUASH_CHUNK_UNCOMPRESSED)
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{
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grub_disk_addr_t a = chunk_start + 2 + offset;
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err = grub_disk_read (disk, (a >> GRUB_DISK_SECTOR_BITS),
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a & (GRUB_DISK_SECTOR_SIZE - 1),
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csize, buf);
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if (err)
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return err;
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}
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else
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{
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char *tmp;
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grub_size_t bsize = grub_le_to_cpu16 (d) & ~SQUASH_CHUNK_FLAGS;
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grub_disk_addr_t a = chunk_start + 2;
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tmp = grub_malloc (bsize);
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if (!tmp)
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return grub_errno;
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/* FIXME: buffer uncompressed data. */
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err = grub_disk_read (disk, (a >> GRUB_DISK_SECTOR_BITS),
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a & (GRUB_DISK_SECTOR_SIZE - 1),
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bsize, tmp);
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if (err)
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{
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grub_free (tmp);
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return err;
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}
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if (grub_zlib_decompress (tmp, bsize, offset,
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buf, csize) < 0)
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{
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grub_free (tmp);
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return grub_errno;
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}
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grub_free (tmp);
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}
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len -= csize;
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offset += csize;
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buf = (char *) buf + csize;
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}
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return GRUB_ERR_NONE;
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}
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static struct grub_squash_data *
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squash_mount (grub_disk_t disk)
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{
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struct grub_squash_super sb;
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grub_err_t err;
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struct grub_squash_data *data;
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grub_uint64_t frag;
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err = grub_disk_read (disk, 0, 0, sizeof (sb), &sb);
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if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
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grub_error (GRUB_ERR_BAD_FS, "not a squash4");
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if (err)
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return NULL;
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if (grub_le_to_cpu32 (sb.magic) != SQUASH_MAGIC)
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{
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grub_error (GRUB_ERR_BAD_FS, "not squash4");
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return NULL;
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}
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err = grub_disk_read (disk, grub_le_to_cpu32 (sb.unk1offset)
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>> GRUB_DISK_SECTOR_BITS,
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grub_le_to_cpu32 (sb.unk1offset)
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& (GRUB_DISK_SECTOR_SIZE - 1), sizeof (frag), &frag);
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if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
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grub_error (GRUB_ERR_BAD_FS, "not a squash4");
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if (err)
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return NULL;
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data = grub_malloc (sizeof (*data));
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if (!data)
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return NULL;
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data->sb = sb;
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data->disk = disk;
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data->fragments = frag;
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return data;
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}
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static int
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grub_squash_iterate_dir (grub_fshelp_node_t dir,
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int NESTED_FUNC_ATTR
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(*hook) (const char *filename,
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enum grub_fshelp_filetype filetype,
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grub_fshelp_node_t node))
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{
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grub_uint32_t off = grub_le_to_cpu32 (dir->ino.offset) >> 16;
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grub_uint32_t endoff;
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unsigned i;
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/* FIXME: why - 3 ? */
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endoff = (grub_le_to_cpu32 (dir->ino.offset) & 0xffff) + off - 3;
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while (off < endoff)
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{
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struct grub_squash_dirent_header dh;
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grub_err_t err;
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err = read_chunk (dir->data->disk, &dh, sizeof (dh),
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grub_le_to_cpu64 (dir->data->sb.diroffset)
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+ grub_le_to_cpu32 (dir->ino.chunk), off);
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if (err)
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return 0;
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off += sizeof (dh);
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for (i = 0; i < (unsigned) grub_le_to_cpu16 (dh.nelems) + 1; i++)
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{
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char *buf;
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int r;
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struct grub_fshelp_node *node;
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enum grub_fshelp_filetype filetype = GRUB_FSHELP_REG;
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struct grub_squash_dirent di;
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struct grub_squash_inode ino;
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err = read_chunk (dir->data->disk, &di, sizeof (di),
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grub_le_to_cpu64 (dir->data->sb.diroffset)
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+ grub_le_to_cpu32 (dir->ino.chunk), off);
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if (err)
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return 0;
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off += sizeof (di);
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err = read_chunk (dir->data->disk, &ino, sizeof (ino),
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grub_le_to_cpu64 (dir->data->sb.inodeoffset)
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+ grub_le_to_cpu32 (dh.ino_chunk),
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grub_cpu_to_le16 (di.ino_offset));
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if (err)
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return 0;
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buf = grub_malloc (grub_le_to_cpu16 (di.namelen) + 2);
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if (!buf)
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return 0;
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err = read_chunk (dir->data->disk, buf,
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grub_le_to_cpu16 (di.namelen) + 1,
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grub_le_to_cpu64 (dir->data->sb.diroffset)
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+ grub_le_to_cpu32 (dir->ino.chunk), off);
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if (err)
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return 0;
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off += grub_le_to_cpu16 (di.namelen) + 1;
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buf[grub_le_to_cpu16 (di.namelen) + 1] = 0;
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if (grub_le_to_cpu16 (di.type) == SQUASH_TYPE_DIR)
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filetype = GRUB_FSHELP_DIR;
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node = grub_malloc (sizeof (*node));
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if (! node)
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return 0;
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*node = *dir;
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node->ino = ino;
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r = hook (buf, filetype, node);
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grub_free (buf);
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if (r)
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return r;
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}
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}
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return 0;
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}
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static grub_err_t
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make_root_node (struct grub_squash_data *data, struct grub_fshelp_node *root)
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{
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grub_memset (root, 0, sizeof (*root));
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root->data = data;
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return read_chunk (data->disk, &root->ino, sizeof (root->ino),
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grub_le_to_cpu64 (data->sb.inodeoffset)
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+ grub_le_to_cpu16 (data->sb.root_ino_chunk),
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grub_cpu_to_le16 (data->sb.root_ino_offset));
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}
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static grub_err_t
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grub_squash_dir (grub_device_t device, const char *path,
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int (*hook) (const char *filename,
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const struct grub_dirhook_info *info))
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{
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auto int NESTED_FUNC_ATTR iterate (const char *filename,
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enum grub_fshelp_filetype filetype,
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grub_fshelp_node_t node);
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int NESTED_FUNC_ATTR iterate (const char *filename,
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enum grub_fshelp_filetype filetype,
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grub_fshelp_node_t node __attribute__ ((unused)))
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{
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struct grub_dirhook_info info;
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grub_memset (&info, 0, sizeof (info));
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info.dir = ((filetype & GRUB_FSHELP_TYPE_MASK) == GRUB_FSHELP_DIR);
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return hook (filename, &info);
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}
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struct grub_squash_data *data = 0;
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struct grub_fshelp_node *fdiro = 0;
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struct grub_fshelp_node root;
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grub_err_t err;
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data = squash_mount (device->disk);
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if (! data)
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return grub_errno;
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err = make_root_node (data, &root);
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if (err)
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return err;
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grub_fshelp_find_file (path, &root, &fdiro, grub_squash_iterate_dir,
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NULL, GRUB_FSHELP_DIR);
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if (!grub_errno)
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grub_squash_iterate_dir (fdiro, iterate);
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grub_free (data);
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return grub_errno;
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}
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static grub_err_t
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grub_squash_open (struct grub_file *file, const char *name)
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{
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struct grub_squash_data *data = 0;
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struct grub_fshelp_node *fdiro = 0;
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struct grub_fshelp_node root;
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grub_err_t err;
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data = squash_mount (file->device->disk);
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if (! data)
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return grub_errno;
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err = make_root_node (data, &root);
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if (err)
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return err;
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grub_fshelp_find_file (name, &root, &fdiro, grub_squash_iterate_dir,
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NULL, GRUB_FSHELP_REG);
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if (grub_errno)
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{
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grub_free (data);
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return grub_errno;
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}
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file->data = data;
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data->ino = fdiro->ino;
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file->size = grub_le_to_cpu32 (fdiro->ino.size);
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return GRUB_ERR_NONE;
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}
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static grub_ssize_t
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grub_squash_read (grub_file_t file, char *buf, grub_size_t len)
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{
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grub_err_t err;
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grub_uint64_t a;
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struct grub_squash_data *data = file->data;
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if (grub_le_to_cpu16 (data->ino.fragment) == 0xffff)
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{
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if (grub_le_to_cpu32 (data->ino.chunk))
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a = grub_le_to_cpu32 (data->ino.chunk);
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else
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a = sizeof (struct grub_squash_super);
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}
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else
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{
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struct grub_squash_frag_desc frag;
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err = read_chunk (file->device->disk, &frag, sizeof (frag),
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data->fragments, sizeof (frag)
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* grub_le_to_cpu16 (data->ino.fragment));
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if (err)
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return -1;
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a = grub_le_to_cpu64 (frag.offset) + grub_le_to_cpu32 (data->ino.chunk);
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}
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a += grub_le_to_cpu32 (data->ino.offset) + file->offset;
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err = grub_disk_read (file->device->disk, a >> GRUB_DISK_SECTOR_BITS,
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a & (GRUB_DISK_SECTOR_SIZE - 1), len, buf);
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if (err)
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return -1;
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return len;
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}
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static grub_err_t
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grub_squash_close (grub_file_t file)
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{
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grub_free (file->data);
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return GRUB_ERR_NONE;
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}
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static struct grub_fs grub_squash_fs =
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{
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.name = "squash4",
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.dir = grub_squash_dir,
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.open = grub_squash_open,
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.read = grub_squash_read,
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.close = grub_squash_close,
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#ifdef GRUB_UTIL
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.reserved_first_sector = 0,
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#endif
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.next = 0
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};
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GRUB_MOD_INIT(squash4)
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{
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grub_fs_register (&grub_squash_fs);
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}
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GRUB_MOD_FINI(squash4)
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{
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grub_fs_unregister (&grub_squash_fs);
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}
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