grub2/0441-Compressed-HFS-support.patch

From 14aa7e045965ce95779e17e20503191f8f6bc160 Mon Sep 17 00:00:00 2001
From: Vladimir 'phcoder' Serbinenko <phcoder@gmail.com>
Date: Tue, 7 May 2013 15:46:17 +0200
Subject: [PATCH 441/482] 	Compressed HFS+ support.

---
 ChangeLog                   |   4 +
 Makefile.util.def           |   1 +
 grub-core/Makefile.core.def |   5 +
 grub-core/fs/hfsplus.c      | 272 +++++++++++++--------------------------
 grub-core/fs/hfspluscomp.c  | 302 ++++++++++++++++++++++++++++++++++++++++++++
 include/grub/hfsplus.h      | 217 +++++++++++++++++++++++++++++++
 6 files changed, 618 insertions(+), 183 deletions(-)
 create mode 100644 grub-core/fs/hfspluscomp.c
 create mode 100644 include/grub/hfsplus.h

diff --git a/ChangeLog b/ChangeLog
index 8b77759..0430249 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2013-05-07  Vladimir Serbinenko  <phcoder@gmail.com>
 
+	Compressed HFS+ support.
+
+2013-05-07  Vladimir Serbinenko  <phcoder@gmail.com>
+
 	* grub-core/commands/videoinfo.c: Use "paletted" rather than "packed
 	pixel".
 
diff --git a/Makefile.util.def b/Makefile.util.def
index 5888314..dc621db 100644
--- a/Makefile.util.def
+++ b/Makefile.util.def
@@ -85,6 +85,7 @@ library = {
   common = grub-core/fs/fshelp.c;
   common = grub-core/fs/hfs.c;
   common = grub-core/fs/hfsplus.c;
+  common = grub-core/fs/hfspluscomp.c;
   common = grub-core/fs/iso9660.c;
   common = grub-core/fs/jfs.c;
   common = grub-core/fs/minix.c;
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 7dc106e..bb62dce 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -1186,6 +1186,11 @@ module = {
 };
 
 module = {
+  name = hfspluscomp;
+  common = fs/hfspluscomp.c;
+};
+
+module = {
   name = iso9660;
   common = fs/iso9660.c;
 };
diff --git a/grub-core/fs/hfsplus.c b/grub-core/fs/hfsplus.c
index a507c0f..7905624 100644
--- a/grub-core/fs/hfsplus.c
+++ b/grub-core/fs/hfsplus.c
@@ -19,6 +19,7 @@
 
 /* HFS+ is documented at http://developer.apple.com/technotes/tn/tn1150.html */
 
+#define grub_fshelp_node grub_hfsplus_file 
 #include <grub/err.h>
 #include <grub/file.h>
 #include <grub/mm.h>
@@ -29,6 +30,7 @@
 #include <grub/fshelp.h>
 #include <grub/hfs.h>
 #include <grub/charset.h>
+#include <grub/hfsplus.h>
 
 GRUB_MOD_LICENSE ("GPLv3+");
 
@@ -36,42 +38,6 @@ GRUB_MOD_LICENSE ("GPLv3+");
 #define GRUB_HFSPLUSX_MAGIC 0x4858
 #define GRUB_HFSPLUS_SBLOCK 2
 
-/* A HFS+ extent.  */
-struct grub_hfsplus_extent
-{
-  /* The first block of a file on disk.  */
-  grub_uint32_t start;
-  /* The amount of blocks described by this extent.  */
-  grub_uint32_t count;
-} __attribute__ ((packed));
-
-/* The descriptor of a fork.  */
-struct grub_hfsplus_forkdata
-{
-  grub_uint64_t size;
-  grub_uint32_t clumpsize;
-  grub_uint32_t blocks;
-  struct grub_hfsplus_extent extents[8];
-} __attribute__ ((packed));
-
-/* The HFS+ Volume Header.  */
-struct grub_hfsplus_volheader
-{
-  grub_uint16_t magic;
-  grub_uint16_t version;
-  grub_uint32_t attributes;
-  grub_uint8_t unused1[12];
-  grub_uint32_t utime;
-  grub_uint8_t unused2[16];
-  grub_uint32_t blksize;
-  grub_uint8_t unused3[60];
-  grub_uint64_t num_serial;
-  struct grub_hfsplus_forkdata allocations_file;
-  struct grub_hfsplus_forkdata extents_file;
-  struct grub_hfsplus_forkdata catalog_file;
-  struct grub_hfsplus_forkdata attrib_file;
-  struct grub_hfsplus_forkdata startup_file;
-} __attribute__ ((packed));
 
 /* The type of node.  */
 enum grub_hfsplus_btnode_type
@@ -82,16 +48,6 @@ enum grub_hfsplus_btnode_type
     GRUB_HFSPLUS_BTNODE_TYPE_MAP = 2,
   };
 
-struct grub_hfsplus_btnode
-{
-  grub_uint32_t next;
-  grub_uint32_t prev;
-  grub_int8_t type;
-  grub_uint8_t height;
-  grub_uint16_t count;
-  grub_uint16_t unused;
-} __attribute__ ((packed));
-
 /* The header of a HFS+ B+ Tree.  */
 struct grub_hfsplus_btheader
 {
@@ -111,35 +67,6 @@ struct grub_hfsplus_btheader
   grub_uint32_t attributes;
 } __attribute__ ((packed));
 
-/* The on disk layout of a catalog key.  */
-struct grub_hfsplus_catkey
-{
-  grub_uint16_t keylen;
-  grub_uint32_t parent;
-  grub_uint16_t namelen;
-  grub_uint16_t name[30];
-} __attribute__ ((packed));
-
-/* The on disk layout of an extent overflow file key.  */
-struct grub_hfsplus_extkey
-{
-  grub_uint16_t keylen;
-  grub_uint8_t type;
-  grub_uint8_t unused;
-  grub_uint32_t fileid;
-  grub_uint32_t start;
-} __attribute__ ((packed));
-
-struct grub_hfsplus_key
-{
-  union
-  {
-    struct grub_hfsplus_extkey extkey;
-    struct grub_hfsplus_catkey catkey;
-    grub_uint16_t keylen;
-  };
-} __attribute__ ((packed));
-
 struct grub_hfsplus_catfile
 {
   grub_uint16_t type;
@@ -162,9 +89,13 @@ struct grub_hfsplus_catfile
 #define GRUB_HFSPLUS_FILEMODE_SYMLINK	0120000
 
 /* Some pre-defined file IDs.  */
-#define GRUB_HFSPLUS_FILEID_ROOTDIR	2
-#define GRUB_HFSPLUS_FILEID_OVERFLOW	3
-#define GRUB_HFSPLUS_FILEID_CATALOG	4
+enum
+  {
+    GRUB_HFSPLUS_FILEID_ROOTDIR = 2,
+    GRUB_HFSPLUS_FILEID_OVERFLOW = 3,
+    GRUB_HFSPLUS_FILEID_CATALOG	= 4,
+    GRUB_HFSPLUS_FILEID_ATTR	= 8
+  };
 
 enum grub_hfsplus_filetype
   {
@@ -177,98 +108,15 @@ enum grub_hfsplus_filetype
 #define GRUB_HFSPLUSX_BINARYCOMPARE	0xBC
 #define GRUB_HFSPLUSX_CASEFOLDING	0xCF
 
-/* Internal representation of a catalog key.  */
-struct grub_hfsplus_catkey_internal
-{
-  grub_uint32_t parent;
-  const grub_uint16_t *name;
-  grub_size_t namelen;
-};
-
-/* Internal representation of an extent overflow key.  */
-struct grub_hfsplus_extkey_internal
-{
-  grub_uint32_t fileid;
-  grub_uint8_t type;
-  grub_uint32_t start;
-};
-
-struct grub_hfsplus_key_internal
-{
-  union
-  {
-    struct grub_hfsplus_extkey_internal extkey;
-    struct grub_hfsplus_catkey_internal catkey;
-  };
-};
-
-
-
-struct grub_fshelp_node
-{
-  struct grub_hfsplus_data *data;
-  struct grub_hfsplus_extent extents[8];
-  grub_uint64_t size;
-  grub_uint32_t fileid;
-  grub_int32_t mtime;
-};
-
-struct grub_hfsplus_btree
-{
-  grub_uint32_t root;
-  grub_size_t nodesize;
-
-  /* Catalog file node.  */
-  struct grub_fshelp_node file;
-};
-
-/* Information about a "mounted" HFS+ filesystem.  */
-struct grub_hfsplus_data
-{
-  struct grub_hfsplus_volheader volheader;
-  grub_disk_t disk;
-
-  unsigned int log2blksize;
-
-  struct grub_hfsplus_btree catalog_tree;
-  struct grub_hfsplus_btree extoverflow_tree;
-
-  struct grub_fshelp_node dirroot;
-  struct grub_fshelp_node opened_file;
-
-  /* This is the offset into the physical disk for an embedded HFS+
-     filesystem (one inside a plain HFS wrapper).  */
-  grub_disk_addr_t embedded_offset;
-  int case_sensitive;
-};
-
 static grub_dl_t my_mod;
 
 
-/* Return the offset of the record with the index INDEX, in the node
-   NODE which is part of the B+ tree BTREE.  */
-static inline grub_off_t
-grub_hfsplus_btree_recoffset (struct grub_hfsplus_btree *btree,
-			   struct grub_hfsplus_btnode *node, int index)
-{
-  char *cnode = (char *) node;
-  void *recptr;
-  recptr = (&cnode[btree->nodesize - index * sizeof (grub_uint16_t) - 2]);
-  return grub_be_to_cpu16 (grub_get_unaligned16 (recptr));
-}
-
-/* Return a pointer to the record with the index INDEX, in the node
-   NODE which is part of the B+ tree BTREE.  */
-static inline struct grub_hfsplus_key *
-grub_hfsplus_btree_recptr (struct grub_hfsplus_btree *btree,
-			   struct grub_hfsplus_btnode *node, int index)
-{
-  char *cnode = (char *) node;
-  grub_off_t offset;
-  offset = grub_hfsplus_btree_recoffset (btree, node, index);
-  return (struct grub_hfsplus_key *) &cnode[offset];
-}
 
+grub_err_t (*grub_hfsplus_open_compressed) (struct grub_fshelp_node *node);
+grub_ssize_t (*grub_hfsplus_read_compressed) (struct grub_hfsplus_file *node,
+					      grub_off_t pos,
+					      grub_size_t len,
+					      char *buf);
 
 /* Find the extent that points to FILEBLOCK.  If it is not in one of
    the 8 extents described by EXTENT, return -1.  In that case set
@@ -292,14 +140,6 @@ grub_hfsplus_find_block (struct grub_hfsplus_extent *extent,
   return 0xffffffffffffffffULL;
 }
 
-static grub_err_t
-grub_hfsplus_btree_search (struct grub_hfsplus_btree *btree,
-			   struct grub_hfsplus_key_internal *key,
-			   int (*compare_keys) (struct grub_hfsplus_key *keya,
-						struct grub_hfsplus_key_internal *keyb),
-			   struct grub_hfsplus_btnode **matchnode, 
-			   grub_off_t *keyoffset);
-
 static int grub_hfsplus_cmp_extkey (struct grub_hfsplus_key *keya,
 				    struct grub_hfsplus_key_internal *keyb);
 
@@ -310,7 +150,8 @@ grub_hfsplus_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
 {
   struct grub_hfsplus_btnode *nnode = 0;
   grub_disk_addr_t blksleft = fileblock;
-  struct grub_hfsplus_extent *extents = &node->extents[0];
+  struct grub_hfsplus_extent *extents = node->compressed 
+    ? &node->resource_extents[0] : &node->extents[0];
 
   while (1)
     {
@@ -344,10 +185,11 @@ grub_hfsplus_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
       extoverflow.extkey.fileid = node->fileid;
       extoverflow.extkey.type = 0;
       extoverflow.extkey.start = fileblock - blksleft;
-
+      extoverflow.extkey.type = node->compressed ? 0xff : 0;
       if (grub_hfsplus_btree_search (&node->data->extoverflow_tree,
 				     &extoverflow,
-				     grub_hfsplus_cmp_extkey, &nnode, &ptr))
+				     grub_hfsplus_cmp_extkey, &nnode, &ptr)
+	  || !nnode)
 	{
 	  grub_error (GRUB_ERR_READ_ERROR,
 		      "no block found for the file id 0x%x and the block offset 0x%x",
@@ -373,7 +215,7 @@ grub_hfsplus_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
 
 /* Read LEN bytes from the file described by DATA starting with byte
    POS.  Return the amount of read bytes in READ.  */
-static grub_ssize_t
+grub_ssize_t
 grub_hfsplus_read_file (grub_fshelp_node_t node,
 			grub_disk_read_hook_t read_hook, void *read_hook_data,
 			grub_off_t pos, grub_size_t len, char *buf)
@@ -460,15 +302,27 @@ grub_hfsplus_mount (grub_disk_t disk)
   /* Make a new node for the catalog tree.  */
   data->catalog_tree.file.data = data;
   data->catalog_tree.file.fileid = GRUB_HFSPLUS_FILEID_CATALOG;
+  data->catalog_tree.file.compressed = 0;
   grub_memcpy (&data->catalog_tree.file.extents,
 	       data->volheader.catalog_file.extents,
 	       sizeof data->volheader.catalog_file.extents);
   data->catalog_tree.file.size =
     grub_be_to_cpu64 (data->volheader.catalog_file.size);
 
+  data->attr_tree.file.data = data;
+  data->attr_tree.file.fileid = GRUB_HFSPLUS_FILEID_ATTR;
+  grub_memcpy (&data->attr_tree.file.extents,
+	       data->volheader.attr_file.extents,
+	       sizeof data->volheader.attr_file.extents);
+
+  data->attr_tree.file.size =
+    grub_be_to_cpu64 (data->volheader.attr_file.size);
+  data->attr_tree.file.compressed = 0;
+
   /* Make a new node for the extent overflow file.  */
   data->extoverflow_tree.file.data = data;
   data->extoverflow_tree.file.fileid = GRUB_HFSPLUS_FILEID_OVERFLOW;
+  data->extoverflow_tree.file.compressed = 0;
   grub_memcpy (&data->extoverflow_tree.file.extents,
 	       data->volheader.extents_file.extents,
 	       sizeof data->volheader.catalog_file.extents);
@@ -501,6 +355,20 @@ grub_hfsplus_mount (grub_disk_t disk)
   data->extoverflow_tree.root = grub_be_to_cpu32 (header.root);
   data->extoverflow_tree.nodesize = grub_be_to_cpu16 (header.nodesize);
 
+  if (grub_hfsplus_read_file (&data->attr_tree.file, 0, 0,
+			      sizeof (struct grub_hfsplus_btnode),
+			      sizeof (header), (char *) &header) <= 0)
+    {
+      grub_errno = 0;
+      data->attr_tree.root = 0;
+      data->attr_tree.nodesize = 0;
+    }
+  else
+    {
+      data->attr_tree.root = grub_be_to_cpu32 (header.root);
+      data->attr_tree.nodesize = grub_be_to_cpu16 (header.nodesize);
+    }
+
   data->dirroot.data = data;
   data->dirroot.fileid = GRUB_HFSPLUS_FILEID_ROOTDIR;
 
@@ -586,6 +454,12 @@ grub_hfsplus_cmp_extkey (struct grub_hfsplus_key *keya,
     return 1;
   if (extkey_a->type < extkey_b->type)
     return -1;
+
+  if (extkey_a->type > extkey_b->type)
+    return +1;
+
+  if (extkey_a->type < extkey_b->type)
+    return -1;
   
   akey = grub_be_to_cpu32 (extkey_a->start);
   if (akey > extkey_b->start)
@@ -668,7 +542,7 @@ grub_hfsplus_btree_iterate_node (struct grub_hfsplus_btree *btree,
    keys using the function COMPARE_KEYS.  When a match is found,
    return the node in MATCHNODE and a pointer to the data in this node
    in KEYOFFSET.  MATCHNODE should be freed by the caller.  */
-static grub_err_t
+grub_err_t
 grub_hfsplus_btree_search (struct grub_hfsplus_btree *btree,
 			   struct grub_hfsplus_key_internal *key,
 			   int (*compare_keys) (struct grub_hfsplus_key *keya,
@@ -683,6 +557,12 @@ grub_hfsplus_btree_search (struct grub_hfsplus_btree *btree,
   grub_uint64_t save_node;
   grub_uint64_t node_count = 0;
 
+  if (!btree->nodesize)
+    {
+      *matchnode = 0;
+      return 0;
+    }
+
   node = grub_malloc (btree->nodesize);
   if (! node)
     return grub_errno;
@@ -760,7 +640,7 @@ grub_hfsplus_btree_search (struct grub_hfsplus_btree *btree,
 	{
 	  *matchnode = 0;
 	  grub_free (node);
-	  return 1;
+	  return 0;
 	}
     }
 }
@@ -872,11 +752,17 @@ list_nodes (void *record, void *hook_arg)
   if (!node)
     return 1;
   node->data = ctx->dir->data;
+  node->compressed = 0;
+  node->cbuf = 0;
+  node->compress_index = 0;
 
   grub_memcpy (node->extents, fileinfo->data.extents,
 	       sizeof (node->extents));
+  grub_memcpy (node->resource_extents, fileinfo->resource.extents,
+	       sizeof (node->resource_extents));
   node->mtime = grub_be_to_cpu32 (fileinfo->mtime) - 2082844800;
   node->size = grub_be_to_cpu64 (fileinfo->data.size);
+  node->resource_size = grub_be_to_cpu64 (fileinfo->resource.size);
   node->fileid = grub_be_to_cpu32 (fileinfo->fileid);
 
   ctx->ret = ctx->hook (filename, type, node, ctx->hook_data);
@@ -919,7 +805,8 @@ grub_hfsplus_iterate_dir (grub_fshelp_node_t dir,
 
   /* First lookup the first entry.  */
   if (grub_hfsplus_btree_search (&dir->data->catalog_tree, &intern,
-				 grub_hfsplus_cmp_catkey, &node, &ptr))
+				 grub_hfsplus_cmp_catkey, &node, &ptr)
+      || !node)
     return 0;
 
   /* Iterate over all entries in this directory.  */
@@ -950,6 +837,14 @@ grub_hfsplus_open (struct grub_file *file, const char *name)
   if (grub_errno)
     goto fail;
 
+  if (grub_hfsplus_open_compressed)
+    {
+      grub_err_t err;
+      err = grub_hfsplus_open_compressed (fdiro);
+      if (err)
+	goto fail;
+    }
+
   file->size = fdiro->size;
   data->opened_file = *fdiro;
   grub_free (fdiro);
@@ -973,7 +868,13 @@ grub_hfsplus_open (struct grub_file *file, const char *name)
 static grub_err_t
 grub_hfsplus_close (grub_file_t file)
 {
-  grub_free (file->data);
+  struct grub_hfsplus_data *data =
+    (struct grub_hfsplus_data *) file->data;
+
+  grub_free (data->opened_file.cbuf);
+  grub_free (data->opened_file.compress_index);
+
+  grub_free (data);
 
   grub_dl_unref (my_mod);
 
@@ -987,6 +888,10 @@ grub_hfsplus_read (grub_file_t file, char *buf, grub_size_t len)
   struct grub_hfsplus_data *data =
     (struct grub_hfsplus_data *) file->data;
 
+  if (grub_hfsplus_read_compressed && data->opened_file.compressed)
+    return grub_hfsplus_read_compressed (&data->opened_file,
+					 file->offset, len, buf);
+
   return grub_hfsplus_read_file (&data->opened_file,
 				 file->read_hook, file->read_hook_data,
 				 file->offset, len, buf);
@@ -1076,7 +981,8 @@ grub_hfsplus_label (grub_device_t device, char **label)
 
   /* First lookup the first entry.  */
   if (grub_hfsplus_btree_search (&data->catalog_tree, &intern,
-				 grub_hfsplus_cmp_catkey_id, &node, &ptr))
+				 grub_hfsplus_cmp_catkey_id, &node, &ptr)
+      || !node)
     {
       grub_free (data);
       return 0;
diff --git a/grub-core/fs/hfspluscomp.c b/grub-core/fs/hfspluscomp.c
new file mode 100644
index 0000000..b343441
--- /dev/null
+++ b/grub-core/fs/hfspluscomp.c
@@ -0,0 +1,302 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2012  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* HFS+ is documented at http://developer.apple.com/technotes/tn/tn1150.html */
+
+#include <grub/hfsplus.h>
+#include <grub/dl.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+#include <grub/deflate.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+/* big-endian.  */
+struct grub_hfsplus_compress_header1
+{
+  grub_uint32_t header_size;
+  grub_uint32_t end_descriptor_offset;
+  grub_uint32_t total_compressed_size_including_seek_blocks_and_header2;
+  grub_uint32_t value_0x32;
+  grub_uint8_t unused[0xf0];
+} __attribute__ ((packed));
+
+/* big-endian.  */
+struct grub_hfsplus_compress_header2
+{
+  grub_uint32_t total_compressed_size_including_seek_blocks;
+} __attribute__ ((packed));
+
+/* little-endian.  */
+struct grub_hfsplus_compress_header3
+{
+  grub_uint32_t num_chunks;
+} __attribute__ ((packed));
+
+/* little-endian.  */
+struct grub_hfsplus_compress_block_descriptor
+{
+  grub_uint32_t offset;
+  grub_uint32_t size;
+};
+
+struct grub_hfsplus_compress_end_descriptor
+{
+  grub_uint8_t always_the_same[50];
+} __attribute__ ((packed));
+
+struct grub_hfsplus_attr_header
+{
+  grub_uint8_t unused[3];
+  grub_uint8_t type;
+  grub_uint32_t unknown[1];
+  grub_uint64_t size;
+} __attribute__ ((packed));
+
+struct grub_hfsplus_compress_attr
+{
+  grub_uint32_t magic;
+  grub_uint32_t type;
+  grub_uint32_t uncompressed_inline_size;
+  grub_uint32_t always_0;
+};
+
+enum
+  {
+    HFSPLUS_COMPRESSION_INLINE = 3,
+    HFSPLUS_COMPRESSION_RESOURCE = 4
+  };
+
+static int
+grub_hfsplus_cmp_attrkey (struct grub_hfsplus_key *keya,
+			  struct grub_hfsplus_key_internal *keyb)
+{
+  struct grub_hfsplus_attrkey *attrkey_a = &keya->attrkey;
+  struct grub_hfsplus_attrkey_internal *attrkey_b = &keyb->attrkey;
+  grub_uint32_t aparent = grub_be_to_cpu32 (attrkey_a->cnid);
+  grub_size_t len;
+  int diff;
+
+  if (aparent > attrkey_b->cnid)
+    return 1;
+  if (aparent < attrkey_b->cnid)
+    return -1;
+
+  len = grub_be_to_cpu16 (attrkey_a->namelen);
+  if (len > attrkey_b->namelen)
+    len = attrkey_b->namelen;
+  /* Since it's big-endian memcmp gives the same result as manually comparing
+     uint16_t but may be faster.  */
+  diff = grub_memcmp (attrkey_a->name, attrkey_b->name,
+		      len * sizeof (attrkey_a->name[0]));
+  if (diff == 0)
+    diff = grub_be_to_cpu16 (attrkey_a->namelen) - attrkey_b->namelen;
+  return diff;
+}
+
+#define HFSPLUS_COMPRESS_BLOCK_SIZE 65536
+
+static grub_ssize_t
+hfsplus_read_compressed_real (struct grub_hfsplus_file *node,
+			      grub_off_t pos, grub_size_t len, char *buf)
+{
+  char *tmp_buf = 0;
+  grub_size_t len0 = len;
+
+  if (node->compressed == 1)
+    {
+      grub_memcpy (buf, node->cbuf + pos, len);
+      return len;
+    }
+
+  while (len)
+    {
+      grub_uint32_t block = pos / HFSPLUS_COMPRESS_BLOCK_SIZE;
+      grub_size_t curlen = HFSPLUS_COMPRESS_BLOCK_SIZE
+	- (pos % HFSPLUS_COMPRESS_BLOCK_SIZE);
+
+      if (curlen > len)
+	curlen = len;
+
+      if (node->cbuf_block != block)
+	{
+	  grub_uint32_t sz = grub_le_to_cpu32 (node->compress_index[block].size);
+	  grub_size_t ts;
+	  if (!tmp_buf)
+	    tmp_buf = grub_malloc (HFSPLUS_COMPRESS_BLOCK_SIZE);
+	  if (!tmp_buf)
+	    return -1;
+	  if (grub_hfsplus_read_file (node, 0, 0,
+				      grub_le_to_cpu32 (node->compress_index[block].start) + 0x104,
+				      sz, tmp_buf)
+	      != (grub_ssize_t) sz)
+	    {
+	      grub_free (tmp_buf);
+	      return -1;
+	    }
+	  ts = HFSPLUS_COMPRESS_BLOCK_SIZE;
+	  if (ts > node->size - (pos & ~(HFSPLUS_COMPRESS_BLOCK_SIZE)))
+	    ts = node->size - (pos & ~(HFSPLUS_COMPRESS_BLOCK_SIZE));
+	  if (grub_zlib_decompress (tmp_buf, sz, 0,
+				    node->cbuf, ts) < 0)
+	    {
+	      grub_free (tmp_buf);
+	      return -1;
+	    }
+	  node->cbuf_block = block;
+	}
+      grub_memcpy (buf, node->cbuf + (pos % HFSPLUS_COMPRESS_BLOCK_SIZE),
+		   curlen);
+      buf += curlen;
+      pos += curlen;
+      len -= curlen;
+    }
+  grub_free (tmp_buf);
+  return len0;
+}
+
+static grub_err_t 
+hfsplus_open_compressed_real (struct grub_hfsplus_file *node)
+{
+  grub_err_t err;
+  struct grub_hfsplus_btnode *attr_node;
+  grub_off_t attr_off;
+  struct grub_hfsplus_key_internal key;
+  struct grub_hfsplus_attr_header *attr_head;
+  struct grub_hfsplus_compress_attr *cmp_head;
+#define c grub_cpu_to_be16_compile_time
+  const grub_uint16_t compress_attr_name[] =
+    {
+      c('c'), c('o'), c('m'), c('.'), c('a'), c('p'), c('p'), c('l'), c('e'),
+      c('.'), c('d'), c('e'), c('c'), c('m'), c('p'), c('f'), c('s') };
+#undef c
+  if (node->size)
+    return 0;
+
+  key.attrkey.cnid = node->fileid;
+  key.attrkey.namelen = sizeof (compress_attr_name) / sizeof (compress_attr_name[0]);
+  key.attrkey.name = compress_attr_name;
+
+  err = grub_hfsplus_btree_search (&node->data->attr_tree, &key,
+				   grub_hfsplus_cmp_attrkey,
+				   &attr_node, &attr_off);
+  if (err || !attr_node)
+    {
+      grub_errno = 0;
+      return 0;
+    }
+
+  attr_head = (struct grub_hfsplus_attr_header *)
+    ((char *) grub_hfsplus_btree_recptr (&node->data->attr_tree,
+					 attr_node, attr_off)
+     + sizeof (struct grub_hfsplus_attrkey) + sizeof (compress_attr_name));
+  if (attr_head->type != 0x10
+      || !(attr_head->size & grub_cpu_to_be64_compile_time(~0xfULL)))
+    {
+      grub_free (attr_node);
+      return 0;
+    }
+  cmp_head = (struct grub_hfsplus_compress_attr *) (attr_head + 1);
+  if (cmp_head->magic != grub_cpu_to_be32_compile_time (0x66706d63))
+    {
+      grub_free (attr_node);
+      return 0;
+    }
+  node->size = grub_le_to_cpu32 (cmp_head->uncompressed_inline_size);
+
+  if (cmp_head->type == grub_cpu_to_le32_compile_time (HFSPLUS_COMPRESSION_RESOURCE))
+    {
+      grub_uint32_t index_size;
+      node->compressed = 2;
+
+      if (grub_hfsplus_read_file (node, 0, 0,
+				  0x104, sizeof (index_size),
+				  (char *) &index_size)
+	  != 4)
+	{
+	  node->compressed = 0;
+	  grub_free (attr_node);
+	  grub_errno = 0;
+	  return 0;
+	}
+      node->compress_index_size = grub_le_to_cpu32 (index_size);
+      node->compress_index = grub_malloc (node->compress_index_size
+					  * sizeof (node->compress_index[0]));
+      if (!node->compress_index)
+	{
+	  node->compressed = 0;
+	  grub_free (attr_node);
+	  return grub_errno;
+	}
+      if (grub_hfsplus_read_file (node, 0, 0,
+				  0x104 + sizeof (index_size),
+				  node->compress_index_size
+				  * sizeof (node->compress_index[0]),
+				  (char *) node->compress_index)
+	  != (grub_ssize_t) (node->compress_index_size
+			     * sizeof (node->compress_index[0])))
+	{
+	  node->compressed = 0;
+	  grub_free (attr_node);
+	  grub_free (node->compress_index);
+	  grub_errno = 0;
+	  return 0;
+	}
+
+      node->cbuf_block = -1;
+
+      node->cbuf = grub_malloc (HFSPLUS_COMPRESS_BLOCK_SIZE);
+      grub_free (attr_node);
+      if (!node->cbuf)
+	{
+	  node->compressed = 0;
+	  grub_free (node->compress_index);
+	  return grub_errno;
+	}
+      return 0;
+    }
+  if (cmp_head->type != HFSPLUS_COMPRESSION_INLINE)
+    {
+      grub_free (attr_node);
+      return 0;
+    }
+
+  node->cbuf = grub_malloc (node->size);
+  if (!node->cbuf)
+    return grub_errno;
+
+  if (grub_zlib_decompress ((char *) (cmp_head + 1),
+			    grub_cpu_to_be64 (attr_head->size)
+			    - sizeof (*cmp_head), 0,
+			    node->cbuf, node->size) < 0)
+    return grub_errno;
+  node->compressed = 1;
+  return 0;
+}
+
+GRUB_MOD_INIT(hfspluscomp)
+{
+  grub_hfsplus_open_compressed = hfsplus_open_compressed_real;  
+  grub_hfsplus_read_compressed = hfsplus_read_compressed_real;  
+}
+
+GRUB_MOD_FINI(hfspluscomp)
+{
+  grub_hfsplus_open_compressed = 0;
+  grub_hfsplus_read_compressed = 0;
+}
diff --git a/include/grub/hfsplus.h b/include/grub/hfsplus.h
new file mode 100644
index 0000000..0defd35
--- /dev/null
+++ b/include/grub/hfsplus.h
@@ -0,0 +1,217 @@
+
+#include <grub/types.h>
+#include <grub/disk.h>
+
+/* A HFS+ extent.  */
+struct grub_hfsplus_extent
+{
+  /* The first block of a file on disk.  */
+  grub_uint32_t start;
+  /* The amount of blocks described by this extent.  */
+  grub_uint32_t count;
+} __attribute__ ((packed));
+
+/* The descriptor of a fork.  */
+struct grub_hfsplus_forkdata
+{
+  grub_uint64_t size;
+  grub_uint32_t clumpsize;
+  grub_uint32_t blocks;
+  struct grub_hfsplus_extent extents[8];
+} __attribute__ ((packed));
+
+/* The HFS+ Volume Header.  */
+struct grub_hfsplus_volheader
+{
+  grub_uint16_t magic;
+  grub_uint16_t version;
+  grub_uint32_t attributes;
+  grub_uint8_t unused1[12];
+  grub_uint32_t utime;
+  grub_uint8_t unused2[16];
+  grub_uint32_t blksize;
+  grub_uint8_t unused3[60];
+  grub_uint64_t num_serial;
+  struct grub_hfsplus_forkdata allocations_file;
+  struct grub_hfsplus_forkdata extents_file;
+  struct grub_hfsplus_forkdata catalog_file;
+  struct grub_hfsplus_forkdata attr_file;
+  struct grub_hfsplus_forkdata startup_file;
+} __attribute__ ((packed));
+
+struct grub_hfsplus_compress_index
+{
+  grub_uint32_t start;
+  grub_uint32_t size;
+};
+
+struct grub_hfsplus_file
+{
+  struct grub_hfsplus_data *data;
+  struct grub_hfsplus_extent extents[8];
+  struct grub_hfsplus_extent resource_extents[8];
+  grub_uint64_t size;
+  grub_uint64_t resource_size;
+  grub_uint32_t fileid;
+  grub_int32_t mtime;
+  int compressed;
+  char *cbuf;
+  struct grub_hfsplus_compress_index *compress_index;
+  grub_uint32_t cbuf_block;
+  grub_uint32_t compress_index_size;
+};
+
+struct grub_hfsplus_btree
+{
+  grub_uint32_t root;
+  grub_size_t nodesize;
+
+  /* Catalog file node.  */
+  struct grub_hfsplus_file file;
+};
+
+/* Information about a "mounted" HFS+ filesystem.  */
+struct grub_hfsplus_data
+{
+  struct grub_hfsplus_volheader volheader;
+  grub_disk_t disk;
+
+  unsigned int log2blksize;
+
+  struct grub_hfsplus_btree catalog_tree;
+  struct grub_hfsplus_btree extoverflow_tree;
+  struct grub_hfsplus_btree attr_tree;
+
+  struct grub_hfsplus_file dirroot;
+  struct grub_hfsplus_file opened_file;
+
+  /* This is the offset into the physical disk for an embedded HFS+
+     filesystem (one inside a plain HFS wrapper).  */
+  grub_disk_addr_t embedded_offset;
+  int case_sensitive;
+};
+
+/* Internal representation of a catalog key.  */
+struct grub_hfsplus_catkey_internal
+{
+  grub_uint32_t parent;
+  const grub_uint16_t *name;
+  grub_size_t namelen;
+};
+
+/* Internal representation of an extent overflow key.  */
+struct grub_hfsplus_extkey_internal
+{
+  grub_uint32_t fileid;
+  grub_uint32_t start;
+  grub_uint8_t type;
+};
+
+struct grub_hfsplus_attrkey
+{
+  grub_uint16_t keylen;
+  grub_uint16_t unknown1[1];
+  grub_uint32_t cnid;
+  grub_uint16_t unknown2[2];
+  grub_uint16_t namelen;
+  grub_uint16_t name[0];
+} __attribute__ ((packed));
+
+struct grub_hfsplus_attrkey_internal
+{
+  grub_uint32_t cnid;
+  const grub_uint16_t *name;
+  grub_size_t namelen;
+};
+
+struct grub_hfsplus_key_internal
+{
+  union
+  {
+    struct grub_hfsplus_extkey_internal extkey;
+    struct grub_hfsplus_catkey_internal catkey;
+    struct grub_hfsplus_attrkey_internal attrkey;
+  };
+};
+
+/* The on disk layout of a catalog key.  */
+struct grub_hfsplus_catkey
+{
+  grub_uint16_t keylen;
+  grub_uint32_t parent;
+  grub_uint16_t namelen;
+  grub_uint16_t name[30];
+} __attribute__ ((packed));
+
+/* The on disk layout of an extent overflow file key.  */
+struct grub_hfsplus_extkey
+{
+  grub_uint16_t keylen;
+  grub_uint8_t type;
+  grub_uint8_t unused;
+  grub_uint32_t fileid;
+  grub_uint32_t start;
+} __attribute__ ((packed));
+
+struct grub_hfsplus_key
+{
+  union
+  {
+    struct grub_hfsplus_extkey extkey;
+    struct grub_hfsplus_catkey catkey;
+    struct grub_hfsplus_attrkey attrkey;
+    grub_uint16_t keylen;
+  };
+} __attribute__ ((packed));
+
+struct grub_hfsplus_btnode
+{
+  grub_uint32_t next;
+  grub_uint32_t prev;
+  grub_int8_t type;
+  grub_uint8_t height;
+  grub_uint16_t count;
+  grub_uint16_t unused;
+} __attribute__ ((packed));
+
+/* Return the offset of the record with the index INDEX, in the node
+   NODE which is part of the B+ tree BTREE.  */
+static inline grub_off_t
+grub_hfsplus_btree_recoffset (struct grub_hfsplus_btree *btree,
+			   struct grub_hfsplus_btnode *node, int index)
+{
+  char *cnode = (char *) node;
+  void *recptr;
+  recptr = (&cnode[btree->nodesize - index * sizeof (grub_uint16_t) - 2]);
+  return grub_be_to_cpu16 (grub_get_unaligned16 (recptr));
+}
+
+/* Return a pointer to the record with the index INDEX, in the node
+   NODE which is part of the B+ tree BTREE.  */
+static inline struct grub_hfsplus_key *
+grub_hfsplus_btree_recptr (struct grub_hfsplus_btree *btree,
+			   struct grub_hfsplus_btnode *node, int index)
+{
+  char *cnode = (char *) node;
+  grub_off_t offset;
+  offset = grub_hfsplus_btree_recoffset (btree, node, index);
+  return (struct grub_hfsplus_key *) &cnode[offset];
+}
+
+extern grub_err_t (*grub_hfsplus_open_compressed) (struct grub_hfsplus_file *node);
+extern grub_ssize_t (*grub_hfsplus_read_compressed) (struct grub_hfsplus_file *node,
+						     grub_off_t pos,
+						     grub_size_t len,
+						     char *buf);
+
+grub_ssize_t
+grub_hfsplus_read_file (struct grub_hfsplus_file *node,
+			grub_disk_read_hook_t read_hook, void *read_hook_data,
+			grub_off_t pos, grub_size_t len, char *buf);
+grub_err_t
+grub_hfsplus_btree_search (struct grub_hfsplus_btree *btree,
+			   struct grub_hfsplus_key_internal *key,
+			   int (*compare_keys) (struct grub_hfsplus_key *keya,
+						struct grub_hfsplus_key_internal *keyb),
+			   struct grub_hfsplus_btnode **matchnode, 
+			   grub_off_t *keyoffset);
-- 
1.8.2.1