613 lines
14 KiB
C
613 lines
14 KiB
C
/* sfs.c - Amiga Smart FileSystem. */
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/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2005,2006,2007,2008 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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/* The common header for a block. */
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struct grub_sfs_bheader
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{
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grub_uint8_t magic[4];
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grub_uint32_t chksum;
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grub_uint32_t ipointtomyself;
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} __attribute__ ((packed));
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/* The sfs rootblock. */
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struct grub_sfs_rblock
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{
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struct grub_sfs_bheader header;
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grub_uint32_t version;
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grub_uint8_t unused1[36];
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grub_uint32_t blocksize;
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grub_uint8_t unused2[40];
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grub_uint8_t unused3[8];
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grub_uint32_t rootobject;
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grub_uint32_t btree;
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} __attribute__ ((packed));
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/* A SFS object container. */
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struct grub_sfs_obj
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{
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grub_uint8_t unused1[4];
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grub_uint32_t nodeid;
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grub_uint8_t unused2[4];
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union
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{
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struct
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{
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grub_uint32_t first_block;
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grub_uint32_t size;
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} file __attribute__ ((packed));
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struct
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{
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grub_uint32_t hashtable;
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grub_uint32_t dir_objc;
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} dir __attribute__ ((packed));
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} file_dir;
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grub_uint8_t unused3[4];
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grub_uint8_t type;
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grub_uint8_t filename[1];
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grub_uint8_t comment[1];
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} __attribute__ ((packed));
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#define GRUB_SFS_TYPE_DELETED 32
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#define GRUB_SFS_TYPE_SYMLINK 64
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#define GRUB_SFS_TYPE_DIR 128
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/* A SFS object container. */
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struct grub_sfs_objc
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{
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struct grub_sfs_bheader header;
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grub_uint32_t parent;
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grub_uint32_t next;
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grub_uint32_t prev;
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/* The amount of objects depends on the blocksize. */
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struct grub_sfs_obj objects[1];
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} __attribute__ ((packed));
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struct grub_sfs_btree_node
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{
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grub_uint32_t key;
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grub_uint32_t data;
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} __attribute__ ((packed));
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struct grub_sfs_btree_extent
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{
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grub_uint32_t key;
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grub_uint32_t next;
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grub_uint32_t prev;
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grub_uint16_t size;
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} __attribute__ ((packed));
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struct grub_sfs_btree
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{
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struct grub_sfs_bheader header;
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grub_uint16_t nodes;
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grub_uint8_t leaf;
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grub_uint8_t nodesize;
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/* Normally this can be kind of node, but just extents are
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supported. */
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struct grub_sfs_btree_node node[1];
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} __attribute__ ((packed));
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struct grub_fshelp_node
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{
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struct grub_sfs_data *data;
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int block;
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int size;
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};
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/* Information about a "mounted" sfs filesystem. */
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struct grub_sfs_data
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{
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struct grub_sfs_rblock rblock;
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struct grub_fshelp_node diropen;
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grub_disk_t disk;
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/* Blocksize in sectors. */
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unsigned int blocksize;
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/* Label of the filesystem. */
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char *label;
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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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/* Lookup the extent starting with BLOCK in the filesystem described
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by DATA. Return the extent size in SIZE and the following extent
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in NEXTEXT. */
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static grub_err_t
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grub_sfs_read_extent (struct grub_sfs_data *data, unsigned int block,
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int *size, int *nextext)
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{
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char *treeblock;
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struct grub_sfs_btree *tree;
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int i;
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int next;
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int prev;
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treeblock = grub_malloc (data->blocksize);
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if (!block)
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return 0;
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next = grub_be_to_cpu32 (data->rblock.btree);
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tree = (struct grub_sfs_btree *) treeblock;
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/* Handle this level in the btree. */
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do
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{
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prev = 0;
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grub_disk_read (data->disk, next, 0, data->blocksize, treeblock);
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if (grub_errno)
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{
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grub_free (treeblock);
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return grub_errno;
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}
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for (i = grub_be_to_cpu16 (tree->nodes) - 1; i >= 0; i--)
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{
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#define EXTNODE(tree, index) \
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((struct grub_sfs_btree_node *) (((char *) &(tree)->node[0]) \
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+ (index) * (tree)->nodesize))
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/* Follow the tree down to the leaf level. */
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if ((grub_be_to_cpu32 (EXTNODE(tree, i)->key) <= block)
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&& !tree->leaf)
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{
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next = grub_be_to_cpu32 (EXTNODE (tree, i)->data);
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break;
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}
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/* If the leaf level is reached, just find the correct extent. */
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if (grub_be_to_cpu32 (EXTNODE (tree, i)->key) == block && tree->leaf)
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{
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struct grub_sfs_btree_extent *extent;
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extent = (struct grub_sfs_btree_extent *) EXTNODE (tree, i);
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/* We found a correct leaf. */
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*size = grub_be_to_cpu16 (extent->size);
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*nextext = grub_be_to_cpu32 (extent->next);
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grub_free (treeblock);
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return 0;
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}
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#undef EXTNODE
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}
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} while (!tree->leaf);
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grub_free (treeblock);
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return grub_error (GRUB_ERR_FILE_READ_ERROR, "SFS extent not found");
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}
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static grub_disk_addr_t
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grub_sfs_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
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{
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int blk = node->block;
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int size = 0;
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int next = 0;
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while (blk)
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{
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grub_err_t err;
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/* In case of the first block we don't have to lookup the
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extent, the minimum size is always 1. */
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if (fileblock == 0)
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return blk;
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err = grub_sfs_read_extent (node->data, blk, &size, &next);
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if (err)
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return 0;
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if (fileblock < (unsigned int) size)
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return fileblock + blk;
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fileblock -= size;
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blk = next;
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}
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grub_error (GRUB_ERR_FILE_READ_ERROR,
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"reading a SFS block outside the extent");
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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_sfs_read_file (grub_fshelp_node_t node,
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void NESTED_FUNC_ATTR (*read_hook) (grub_disk_addr_t sector,
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unsigned offset, unsigned length),
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int pos, grub_size_t len, char *buf)
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{
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return grub_fshelp_read_file (node->data->disk, node, read_hook,
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pos, len, buf, grub_sfs_read_block,
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node->size, 0);
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}
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static struct grub_sfs_data *
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grub_sfs_mount (grub_disk_t disk)
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{
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struct grub_sfs_data *data;
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struct grub_sfs_objc *rootobjc;
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char *rootobjc_data = 0;
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unsigned int blk;
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data = grub_malloc (sizeof (*data));
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if (!data)
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return 0;
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/* Read the rootblock. */
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grub_disk_read (disk, 0, 0, sizeof (struct grub_sfs_rblock),
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(char *) &data->rblock);
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if (grub_errno)
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goto fail;
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/* Make sure this is a sfs filesystem. */
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if (grub_strncmp ((char *) (data->rblock.header.magic), "SFS", 4))
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{
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grub_error (GRUB_ERR_BAD_FS, "not a sfs filesystem");
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goto fail;
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}
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data->blocksize = grub_be_to_cpu32 (data->rblock.blocksize);
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rootobjc_data = grub_malloc (data->blocksize);
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if (! rootobjc_data)
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goto fail;
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/* Read the root object container. */
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grub_disk_read (disk, grub_be_to_cpu32 (data->rblock.rootobject), 0,
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data->blocksize, rootobjc_data);
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if (grub_errno)
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goto fail;
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rootobjc = (struct grub_sfs_objc *) rootobjc_data;
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blk = grub_be_to_cpu32 (rootobjc->objects[0].file_dir.dir.dir_objc);
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data->diropen.size = 0;
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data->diropen.block = blk;
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data->diropen.data = data;
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data->disk = disk;
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data->label = grub_strdup ((char *) (rootobjc->objects[0].filename));
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return data;
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fail:
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if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
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grub_error (GRUB_ERR_BAD_FS, "not an sfs filesystem");
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grub_free (data);
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grub_free (rootobjc_data);
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return 0;
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}
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static char *
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grub_sfs_read_symlink (grub_fshelp_node_t node)
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{
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struct grub_sfs_data *data = node->data;
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char *symlink;
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char *block;
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block = grub_malloc (data->blocksize);
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if (!block)
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return 0;
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grub_disk_read (data->disk, node->block, 0, data->blocksize, block);
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if (grub_errno)
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{
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grub_free (block);
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return 0;
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}
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/* This is just a wild guess, but it always worked for me. How the
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SLNK block looks like is not documented in the SFS docs. */
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symlink = grub_strdup (&block[24]);
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grub_free (block);
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if (!symlink)
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return 0;
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return symlink;
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}
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static int
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grub_sfs_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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struct grub_fshelp_node *node = 0;
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struct grub_sfs_data *data = dir->data;
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char *objc_data;
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struct grub_sfs_objc *objc;
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unsigned int next = dir->block;
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int pos;
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auto int NESTED_FUNC_ATTR grub_sfs_create_node (const char *name, int block,
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int size, int type);
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int NESTED_FUNC_ATTR grub_sfs_create_node (const char *name, int block,
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int size, int type)
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{
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node = grub_malloc (sizeof (*node));
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if (!node)
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return 1;
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node->data = data;
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node->size = size;
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node->block = block;
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return hook (name, type, node);
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}
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objc_data = grub_malloc (data->blocksize);
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if (!objc_data)
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goto fail;
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/* The Object container can consist of multiple blocks, iterate over
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every block. */
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while (next)
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{
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grub_disk_read (data->disk, next, 0, data->blocksize, objc_data);
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if (grub_errno)
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goto fail;
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objc = (struct grub_sfs_objc *) objc_data;
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pos = (char *) &objc->objects[0] - (char *) objc;
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/* Iterate over all entries in this block. */
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while (pos + sizeof (struct grub_sfs_obj) < data->blocksize)
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{
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struct grub_sfs_obj *obj;
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obj = (struct grub_sfs_obj *) ((char *) objc + pos);
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char *filename = (char *) (obj->filename);
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int len;
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enum grub_fshelp_filetype type;
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unsigned int block;
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/* The filename and comment dynamically increase the size of
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the object. */
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len = grub_strlen (filename);
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len += grub_strlen (filename + len + 1);
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pos += sizeof (*obj) + len;
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/* Round up to a multiple of two bytes. */
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pos = ((pos + 1) >> 1) << 1;
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if (grub_strlen (filename) == 0)
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continue;
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/* First check if the file was not deleted. */
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if (obj->type & GRUB_SFS_TYPE_DELETED)
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continue;
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else if (obj->type & GRUB_SFS_TYPE_SYMLINK)
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type = GRUB_FSHELP_SYMLINK;
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else if (obj->type & GRUB_SFS_TYPE_DIR)
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type = GRUB_FSHELP_DIR;
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else
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type = GRUB_FSHELP_REG;
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if (type == GRUB_FSHELP_DIR)
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block = grub_be_to_cpu32 (obj->file_dir.dir.dir_objc);
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else
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block = grub_be_to_cpu32 (obj->file_dir.file.first_block);
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if (grub_sfs_create_node (filename, block,
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grub_be_to_cpu32 (obj->file_dir.file.size),
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type))
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{
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grub_free (objc_data);
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return 1;
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}
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}
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next = grub_be_to_cpu32 (objc->next);
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}
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fail:
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grub_free (objc_data);
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return 0;
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}
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/* Open a file named NAME and initialize FILE. */
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static grub_err_t
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grub_sfs_open (struct grub_file *file, const char *name)
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{
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struct grub_sfs_data *data;
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struct grub_fshelp_node *fdiro = 0;
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#ifndef GRUB_UTIL
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grub_dl_ref (my_mod);
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#endif
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data = grub_sfs_mount (file->device->disk);
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if (!data)
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goto fail;
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grub_fshelp_find_file (name, &data->diropen, &fdiro, grub_sfs_iterate_dir,
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grub_sfs_read_symlink, GRUB_FSHELP_REG);
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if (grub_errno)
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goto fail;
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file->size = fdiro->size;
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data->diropen = *fdiro;
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grub_free (fdiro);
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file->data = data;
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file->offset = 0;
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return 0;
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fail:
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if (data && fdiro != &data->diropen)
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grub_free (fdiro);
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if (data)
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grub_free (data->label);
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grub_free (data);
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#ifndef GRUB_UTIL
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grub_dl_unref (my_mod);
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#endif
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return grub_errno;
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}
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static grub_err_t
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grub_sfs_close (grub_file_t file)
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{
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grub_free (file->data);
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#ifndef GRUB_UTIL
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grub_dl_unref (my_mod);
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#endif
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return GRUB_ERR_NONE;
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}
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/* Read LEN bytes data from FILE into BUF. */
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static grub_ssize_t
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grub_sfs_read (grub_file_t file, char *buf, grub_size_t len)
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{
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struct grub_sfs_data *data = (struct grub_sfs_data *) file->data;
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int size = grub_sfs_read_file (&data->diropen, file->read_hook,
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file->offset, len, buf);
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return size;
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}
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static grub_err_t
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grub_sfs_dir (grub_device_t device, const char *path,
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int (*hook) (const char *filename, int dir))
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{
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struct grub_sfs_data *data = 0;
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struct grub_fshelp_node *fdiro = 0;
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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)
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{
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grub_free (node);
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if (filetype == GRUB_FSHELP_DIR)
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return hook (filename, 1);
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else
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return hook (filename, 0);
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return 0;
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}
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#ifndef GRUB_UTIL
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grub_dl_ref (my_mod);
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#endif
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data = grub_sfs_mount (device->disk);
|
||
if (!data)
|
||
goto fail;
|
||
|
||
grub_fshelp_find_file (path, &data->diropen, &fdiro, grub_sfs_iterate_dir,
|
||
grub_sfs_read_symlink, GRUB_FSHELP_DIR);
|
||
if (grub_errno)
|
||
goto fail;
|
||
|
||
grub_sfs_iterate_dir (fdiro, iterate);
|
||
|
||
fail:
|
||
if (data && fdiro != &data->diropen)
|
||
grub_free (fdiro);
|
||
if (data)
|
||
grub_free (data->label);
|
||
grub_free (data);
|
||
|
||
#ifndef GRUB_UTIL
|
||
grub_dl_unref (my_mod);
|
||
#endif
|
||
|
||
return grub_errno;
|
||
}
|
||
|
||
|
||
static grub_err_t
|
||
grub_sfs_label (grub_device_t device, char **label)
|
||
{
|
||
struct grub_sfs_data *data;
|
||
grub_disk_t disk = device->disk;
|
||
|
||
data = grub_sfs_mount (disk);
|
||
if (data)
|
||
*label = data->label;
|
||
|
||
grub_free (data);
|
||
|
||
return grub_errno;
|
||
}
|
||
|
||
|
||
static struct grub_fs grub_sfs_fs =
|
||
{
|
||
.name = "sfs",
|
||
.dir = grub_sfs_dir,
|
||
.open = grub_sfs_open,
|
||
.read = grub_sfs_read,
|
||
.close = grub_sfs_close,
|
||
.label = grub_sfs_label,
|
||
.next = 0
|
||
};
|
||
|
||
GRUB_MOD_INIT(sfs)
|
||
{
|
||
grub_fs_register (&grub_sfs_fs);
|
||
#ifndef GRUB_UTIL
|
||
my_mod = mod;
|
||
#endif
|
||
}
|
||
|
||
GRUB_MOD_FINI(sfs)
|
||
{
|
||
grub_fs_unregister (&grub_sfs_fs);
|
||
}
|