--- /dev/null
+/*
+ * libhfs - library for reading and writing Macintosh HFS volumes
+ *
+ * Code to acces the basic volume information of a HFS+ volume.
+ *
+ * Copyright (C) 2000 Klaus Halfmann <khalfmann@libra.de>
+ * Original work by 1996-1998 Robert Leslie <rob@mars.org>
+ * other work 2000 from Brad Boyer (flar@pants.nu)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ * $Id: volume.c,v 1.21 2000/10/25 05:43:04 hasi Exp $
+ */
+
+#include "config.h"
+#include "libhfsp.h"
+#include "volume.h"
+#include "record.h"
+#include "btree.h"
+#include "blockiter.h"
+#include "os.h"
+#include "swab.h"
+#include "hfstime.h"
+
+
+/* Fill a given buffer with the given block in volume.
+ */
+int
+volume_readinbuf(volume * vol,void* buf, long block)
+{
+ UInt16 blksize_bits;
+ ASSERT( block < vol->maxblocks);
+
+ blksize_bits = vol->blksize_bits;
+ block += vol->startblock;
+ if( os_seek(vol->os_fd, block, blksize_bits) == block)
+ if( 1 == os_read(vol->os_fd, buf, 1, blksize_bits))
+ return 0;
+ return -1;
+}
+
+/* read multiple blocks into given memory.
+ *
+ * returns given pinter or NULL on failure.
+ */
+void*
+volume_readfromfork(volume* vol, void* buf,
+ hfsp_fork_raw* f, UInt32 block,
+ UInt32 count, UInt8 forktype, UInt32 fileId)
+{
+ blockiter iter;
+ char *cbuf = buf;
+
+ blockiter_init(&iter, vol, f, forktype, fileId);
+ if( blockiter_skip(&iter, block))
+ return NULL;
+
+ while( count > 0) {
+ --count;
+ if( volume_readinbuf(vol, cbuf, blockiter_curr(&iter)))
+ return NULL;
+ cbuf += vol->blksize;
+ if( count > 0 && blockiter_next(&iter))
+ return NULL;
+ }
+ return buf;
+}
+
+
+/* Read a raw hfsp_extent_rec from memory.
+ *
+ * return pointer right after the structure.
+ */
+void*
+volume_readextent(void *p, hfsp_extent_rec er)
+{
+ int i;
+ hfsp_extent *e;
+
+ for( i=0; i < 8; i++) {
+ e = &er[i];
+ e->start_block = bswabU32_inc(p);
+ e->block_count = bswabU32_inc(p);
+ }
+ return p;
+}
+
+/* Read a raw hfsp_fork from memory.
+ *
+ * return pointer right after the structure.
+ */
+void*
+volume_readfork(void *p, hfsp_fork_raw* f)
+{
+ f->total_size = bswabU64_inc(p);
+ f->clump_size = bswabU32_inc(p);
+ f->total_blocks = bswabU32_inc(p);
+
+ return volume_readextent(p, f->extents);
+}
+
+/* Read the volume from the given buffer and swap the bytes.
+ *
+ * ToDo: add more consitency checks.
+ */
+static int
+volume_readbuf(hfsp_vh* vh, char * p)
+{
+ if( (vh->signature = bswabU16_inc(p)) != HFSP_VOLHEAD_SIG)
+ HFSP_ERROR(-1, "This is not a HFS+ volume");
+
+ vh->version = bswabU16_inc(p);
+ vh->attributes = bswabU32_inc(p);
+ vh->last_mount_vers = bswabU32_inc(p);
+ vh->reserved = bswabU32_inc(p);
+ vh->create_date = bswabU32_inc(p);
+ vh->modify_date = bswabU32_inc(p);
+ vh->backup_date = bswabU32_inc(p);
+ vh->checked_date = bswabU32_inc(p);
+ vh->file_count = bswabU32_inc(p);
+ vh->folder_count = bswabU32_inc(p);
+ vh->blocksize = bswabU32_inc(p);
+ vh->total_blocks = bswabU32_inc(p);
+ vh->free_blocks = bswabU32_inc(p);
+ vh->next_alloc = bswabU32_inc(p);
+ vh->rsrc_clump_sz = bswabU32_inc(p);
+ vh->data_clump_sz = bswabU32_inc(p);
+ vh->next_cnid = bswabU32_inc(p);
+ vh->write_count = bswabU32_inc(p);
+ vh->encodings_bmp = bswabU64_inc(p);
+ memcpy(vh->finder_info, p, 32);
+ p += 32; // So finderinfo must be swapped later, ***
+ p = volume_readfork(p, &vh->alloc_file );
+ p = volume_readfork(p, &vh->ext_file );
+ p = volume_readfork(p, &vh->cat_file );
+ p = volume_readfork(p, &vh->attr_file );
+ volume_readfork(p, &vh->start_file );
+ return 0;
+ fail:
+ return -1;
+}
+
+/* Read the volume from the given block */
+static int
+volume_read(volume * vol, hfsp_vh* vh, UInt32 block)
+{
+ char buf[vol->blksize];
+
+ if( volume_readinbuf(vol, buf, block))
+ return -1;
+ return volume_readbuf(vh, buf);
+}
+
+/* Find out wether the volume is wrapped and unwrap it eventually */
+static int
+volume_read_wrapper(volume * vol, hfsp_vh* vh)
+{
+ UInt16 signature;
+ char buf[vol->blksize];
+ char *p = buf;
+ int ret;
+ UInt64 vol_size;
+
+ if( volume_readinbuf(vol, buf, 2) ) // Wrapper or volume header starts here
+ return -1;
+
+ signature = bswabU16_inc(p);
+ if( signature == HFS_VOLHEAD_SIG) { /* Wrapper */
+ UInt32 drAlBlkSiz; /* size (in bytes) of allocation blocks */
+ UInt32 sect_per_block; /* how may block build an hfs sector */
+ UInt16 drAlBlSt; /* first allocation block in volume */
+ UInt16 embeds, embedl; /* Start/lenght of embedded area in blocks */
+
+ p += 0x12; /* skip unneded HFS vol fields */
+ drAlBlkSiz = bswabU32_inc(p); /* offset 0x14 */
+ p += 0x4; /* skip unneded HFS vol fields */
+ drAlBlSt = bswabU16_inc(p); /* offset 0x1C */
+
+ p += 0x5E; /* skip unneded HFS vol fields */
+ signature = bswabU16_inc(p); /* offset 0x7C, drEmbedSigWord */
+ if( signature != HFSP_VOLHEAD_SIG)
+ HFSP_ERROR(-1, "This looks like a normal HFS volume");
+ embeds = bswabU16_inc(p);
+ embedl = bswabU16_inc(p);
+ sect_per_block = (drAlBlkSiz / HFSP_BLOCKSZ);
+ // end is absolute (not relative to HFS+ start)
+ vol->maxblocks = embedl * sect_per_block;
+ vol->startblock = drAlBlSt + embeds * sect_per_block;
+ /* Now we can try to read the embedded HFS+ volume header */
+ return volume_read(vol,vh,2);
+ }
+ else if( signature == HFSP_VOLHEAD_SIG) { /* Native HFS+ volume */
+ p = buf; // Restore to begin of block
+ ret = volume_readbuf(vh, p);
+ if( !ret ) {
+ /* When reading the initial partition we must use 512 byte blocks */
+ vol_size = (uint64_t)vh->blocksize * vh->total_blocks;
+ vol->maxblocks = vol_size / HFSP_BLOCKSZ;
+ }
+
+ return ret;
+ } else
+ HFSP_ERROR(-1, "Neither Wrapper nor native HFS+ volume header found");
+fail:
+ return -1;
+}
+
+
+/* Open the device, read and verify the volume header
+ (and its backup) */
+int
+volume_open( volume* vol, int os_fd )
+{
+ hfsp_vh backup; /* backup volume found at second to last block */
+ long sect_per_block;
+ int shift;
+
+ vol->blksize_bits = HFSP_BLOCKSZ_BITS;
+ vol->blksize = HFSP_BLOCKSZ;
+ vol->startblock = 0;
+ vol->maxblocks = 3;
+ /* this should be enough until we find the volume descriptor */
+ vol->extents = NULL; /* Thanks to Jeremias Sauceda */
+
+ btree_reset(&vol->catalog);
+ vol->os_fd = os_fd;
+
+ // vol->maxblocks = os_seek(vol->os_fd, -1, HFSP_BLOCKSZ_BITS);
+ // This wont work for /dev/... but we do not really need it
+
+ if( volume_read_wrapper(vol, &vol->vol))
+ return -1;
+ if( volume_read(vol, &backup, vol->maxblocks - 2))
+ return -1;
+
+ /* Now switch blksize from HFSP_BLOCKSZ (512) to value given in header
+ and adjust depend values accordingly, after that a block always
+ means a HFS+ allocation size */
+
+ /* Usually 4096 / 512 == 8 */
+ sect_per_block = vol->vol.blocksize / HFSP_BLOCKSZ;
+ shift = 0;
+ if( sect_per_block > 1) {
+ shift = 1;
+ while( sect_per_block > 2) {
+ sect_per_block >>=1;
+ shift++;
+ } /* shift = 3 */
+ }
+ vol -> blksize_bits += shift;
+ vol -> blksize = 1 << vol->blksize_bits;
+ vol -> startblock >>= shift;
+ vol -> maxblocks = vol->vol.total_blocks; /* cant calculate via shift ? */
+
+ if( btree_init_cat(&vol->catalog, vol, &vol->vol.cat_file))
+ return -1;
+
+ return 0;
+}
+
+/* Write back all data eventually cached and close the device */
+int
+volume_close(volume* vol)
+{
+ btree_close(&vol->catalog);
+ if( vol->extents) {
+ btree_close(vol->extents);
+ FREE(vol->extents);
+ }
+ return 0;
+}
+
+/* internal fucntion used to create the extents btree,
+ is called by inline function when needed */
+void
+volume_create_extents_tree(volume* vol)
+{
+ btree* result = (btree*) ALLOC(btree*, sizeof(btree));
+ if( !result)
+ HFSP_ERROR(ENOMEM, "No memory for extents btree");
+ if( !btree_init_extent(result, vol, &vol->vol.ext_file)) {
+ vol->extents = result;
+ return;
+ }
+ fail:
+ vol->extents = NULL;
+}
+
+/* Determine whether the volume is a HFS-plus volume */
+int
+volume_probe(int fd, long long offset)
+{
+ UInt16 *vol;
+ int ret = 0;
+
+ vol = (UInt16 *)malloc(2 * 1 << HFSP_BLOCKSZ_BITS);
+ os_seek_offset( fd, 2 * (1 << HFSP_BLOCKSZ_BITS) + offset );
+ os_read(fd, vol, 2, HFSP_BLOCKSZ_BITS);
+
+ if (__be16_to_cpu(vol[0]) == HFS_VOLHEAD_SIG &&
+ __be16_to_cpu(vol[0x3e]) == HFSP_VOLHEAD_SIG) {
+ ret = -1;
+ } else if (__be16_to_cpu(vol[0]) == HFSP_VOLHEAD_SIG) {
+ ret = -1;
+ }
+
+ free(vol);
+ return ret;
+}
+
Code Review / kvmfornfv.git / blobdiff