merge mainline into net

grub-core/io/lzopio.c

@@ -0,0 +1,564 @@
+/* lzopio.c - decompression support for lzop */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2011  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/>.
+ */
+
+#include <grub/err.h>
+#include <grub/mm.h>
+#include <grub/file.h>
+#include <grub/fs.h>
+#include <grub/dl.h>
+#include <grub/crypto.h>
+#include <minilzo.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+#define LZOP_MAGIC "\x89\x4c\x5a\x4f\x00\x0d\x0a\x1a\x0a"
+#define LZOP_MAGIC_SIZE 9
+#define LZOP_CHECK_SIZE 4
+#define LZOP_NEW_LIB 0x0940
+
+/* Header flags - copied from conf.h of LZOP source code.  */
+#define F_ADLER32_D	0x00000001L
+#define F_ADLER32_C	0x00000002L
+#define F_STDIN		0x00000004L
+#define F_STDOUT	0x00000008L
+#define F_NAME_DEFAULT	0x00000010L
+#define F_DOSISH	0x00000020L
+#define F_H_EXTRA_FIELD	0x00000040L
+#define F_H_GMTDIFF	0x00000080L
+#define F_CRC32_D	0x00000100L
+#define F_CRC32_C	0x00000200L
+#define F_MULTIPART	0x00000400L
+#define F_H_FILTER	0x00000800L
+#define F_H_CRC32	0x00001000L
+#define F_H_PATH	0x00002000L
+#define F_MASK		0x00003FFFL
+
+struct block_header
+{
+  grub_uint32_t usize;
+  grub_uint32_t csize;
+  grub_uint32_t ucheck;
+  grub_uint32_t ccheck;
+  unsigned char *cdata;
+  unsigned char *udata;
+};
+
+struct grub_lzopio
+{
+  grub_file_t file;
+  int has_ccheck;
+  int has_ucheck;
+  const gcry_md_spec_t *ucheck_fun;
+  const gcry_md_spec_t *ccheck_fun;
+  grub_off_t saved_off;		/* Rounded down to block boundary.  */
+  grub_off_t start_block_off;
+  struct block_header block;
+};
+
+typedef struct grub_lzopio *grub_lzopio_t;
+static struct grub_fs grub_lzopio_fs;
+
+/* Some helper functions. On errors memory allocated by those function is free
+ * either on close() so no risk of leaks. This makes functions simpler.  */
+
+/* Read block header from file, after successful exit file points to
+ * beginning of block data.  */
+static int
+read_block_header (struct grub_lzopio *lzopio)
+{
+  lzopio->saved_off += lzopio->block.usize;
+
+  /* Free cached block data if any.  */
+  grub_free (lzopio->block.udata);
+  grub_free (lzopio->block.cdata);
+  lzopio->block.udata = NULL;
+  lzopio->block.cdata = NULL;
+
+  if (grub_file_read (lzopio->file, &lzopio->block.usize,
+		      sizeof (lzopio->block.usize)) !=
+      sizeof (lzopio->block.usize))
+    return -1;
+
+  lzopio->block.usize = grub_be_to_cpu32 (lzopio->block.usize);
+
+  /* Last block has uncompressed data size == 0 and no other fields.  */
+  if (lzopio->block.usize == 0)
+    {
+      if (grub_file_tell (lzopio->file) == grub_file_size (lzopio->file))
+	return 0;
+      else
+	return -1;
+    }
+
+  /* Read compressed data block size.  */
+  if (grub_file_read (lzopio->file, &lzopio->block.csize,
+		      sizeof (lzopio->block.csize)) !=
+      sizeof (lzopio->block.csize))
+    return -1;
+
+  lzopio->block.csize = grub_be_to_cpu32 (lzopio->block.csize);
+
+  /* Corrupted.  */
+  if (lzopio->block.csize > lzopio->block.usize)
+    return -1;
+
+  /* Read checksum of uncompressed data.  */
+  if (lzopio->has_ucheck)
+    {
+      if (grub_file_read (lzopio->file, &lzopio->block.ucheck,
+			  sizeof (lzopio->block.ucheck)) !=
+	  sizeof (lzopio->block.ucheck))
+	return -1;
+
+      lzopio->block.ucheck = grub_be_to_cpu32 (lzopio->block.ucheck);
+    }
+
+  /* Read checksum of compressed data.  */
+  if (lzopio->has_ccheck)
+    {
+      /* Incompressible data block.  */
+      if (lzopio->block.csize == lzopio->block.usize)
+	{
+	  lzopio->block.ccheck = lzopio->block.ucheck;
+	}
+      else
+	{
+	  if (grub_file_read (lzopio->file, &lzopio->block.ccheck,
+			      sizeof (lzopio->block.ccheck)) !=
+	      sizeof (lzopio->block.ccheck))
+	    return -1;
+
+	  lzopio->block.ccheck = grub_be_to_cpu32 (lzopio->block.ccheck);
+	}
+    }
+
+  return 0;
+}
+
+/* Read block data into memory. File must be set to beginning of block data.
+ * Can't be called on last block.  */
+static int
+read_block_data (struct grub_lzopio *lzopio)
+{
+  lzopio->block.cdata = grub_malloc (lzopio->block.csize);
+  if (!lzopio->block.cdata)
+    return -1;
+
+  if (grub_file_read (lzopio->file, lzopio->block.cdata, lzopio->block.csize)
+      != (grub_ssize_t) lzopio->block.csize)
+    return -1;
+
+  if (lzopio->ccheck_fun)
+    {
+      grub_uint64_t context[(lzopio->ccheck_fun->contextsize + 7) / 8];
+
+      lzopio->ccheck_fun->init (context);
+      lzopio->ccheck_fun->write (context, lzopio->block.cdata,
+				 lzopio->block.csize);
+      lzopio->ccheck_fun->final (context);
+
+      if (grub_memcmp
+	  (lzopio->ccheck_fun->read (context), &lzopio->block.ccheck,
+	   sizeof (lzopio->block.ccheck)) != 0)
+	return -1;
+    }
+
+  return 0;
+}
+
+/* Read block data, uncompressed and also store it in memory.  */
+/* XXX Investigate possibility of in-place decompression to reduce memory
+ * footprint. Or try to uncompress directly to buf if possible.  */
+static int
+uncompress_block (struct grub_lzopio *lzopio)
+{
+  lzo_uint usize = lzopio->block.usize;
+
+  if (read_block_data (lzopio) < 0)
+    return -1;
+
+  /* Incompressible data. */
+  if (lzopio->block.csize == lzopio->block.usize)
+    {
+      lzopio->block.udata = lzopio->block.cdata;
+      lzopio->block.cdata = NULL;
+    }
+  else
+    {
+      lzopio->block.udata = grub_malloc (lzopio->block.usize);
+      if (!lzopio->block.udata)
+	return -1;
+
+      if (lzo1x_decompress_safe (lzopio->block.cdata, lzopio->block.csize,
+				 lzopio->block.udata, &usize, NULL)
+	  != LZO_E_OK)
+	return -1;
+
+      if (lzopio->ucheck_fun)
+	{
+	  grub_uint64_t context[(lzopio->ccheck_fun->contextsize + 7) / 8];
+
+	  lzopio->ucheck_fun->init (context);
+	  lzopio->ucheck_fun->write (context, lzopio->block.udata,
+				     lzopio->block.usize);
+	  lzopio->ucheck_fun->final (context);
+
+	  if (grub_memcmp
+	      (lzopio->ucheck_fun->read (context), &lzopio->block.ucheck,
+	       sizeof (lzopio->block.ucheck)) != 0)
+	    return -1;
+	}
+
+      /* Compressed data can be free now.  */
+      grub_free (lzopio->block.cdata);
+      lzopio->block.cdata = NULL;
+    }
+
+  return 0;
+}
+
+/* Jump to next block and read its header.  */
+static int
+jump_block (struct grub_lzopio *lzopio)
+{
+  /* only jump if block was not decompressed (and read from disk) */
+  if (!lzopio->block.udata)
+    {
+      grub_off_t off = grub_file_tell (lzopio->file) + lzopio->block.csize;
+
+      if (grub_file_seek (lzopio->file, off) == ((grub_off_t) - 1))
+	return -1;
+    }
+
+  return read_block_header (lzopio);
+}
+
+static int
+calculate_uncompressed_size (grub_file_t file)
+{
+  grub_lzopio_t lzopio = file->data;
+  grub_off_t usize_total = 0;
+
+  if (read_block_header (lzopio) < 0)
+    return -1;
+
+  /* FIXME: Don't do this for not easily seekable files.  */
+  while (lzopio->block.usize != 0)
+    {
+      usize_total += lzopio->block.usize;
+
+      if (jump_block (lzopio) < 0)
+	return -1;
+    }
+
+  file->size = usize_total;
+
+  return 0;
+}
+
+struct lzop_header
+{
+  grub_uint8_t magic[LZOP_MAGIC_SIZE];
+  grub_uint16_t lzop_version;
+  grub_uint16_t lib_version;
+  grub_uint16_t lib_version_ext;
+  grub_uint8_t method;
+  grub_uint8_t level;
+  grub_uint32_t flags;
+  /* grub_uint32_t filter; */ /* No filters support. Rarely used anyway.  */
+  grub_uint32_t mode;
+  grub_uint32_t mtime_lo;
+  grub_uint32_t mtime_hi;
+  grub_uint8_t name_len;
+} __attribute__ ((packed));
+
+static int
+test_header (grub_file_t file)
+{
+  grub_lzopio_t lzopio = file->data;
+  struct lzop_header header;
+  grub_uint32_t flags, checksum;
+  const gcry_md_spec_t *hcheck;
+  grub_uint8_t *context = NULL;
+  grub_uint8_t *name = NULL;
+
+  if (grub_file_read (lzopio->file, &header, sizeof (header)) != sizeof (header))
+    {
+      grub_error (GRUB_ERR_BAD_FILE_TYPE, "no lzop magic found");
+      return 0;
+    }
+
+  if (grub_memcmp (header.magic, LZOP_MAGIC, LZOP_MAGIC_SIZE) != 0)
+    {
+      grub_error (GRUB_ERR_BAD_FILE_TYPE, "no lzop magic found");
+      return 0;
+    }
+
+  if (grub_be_to_cpu16(header.lib_version) < LZOP_NEW_LIB)
+    {
+      grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
+		  "unsupported (too old) LZOP version");
+      return 0;
+    }
+
+  /* Too new version, should upgrade minilzo?  */
+  if (grub_be_to_cpu16 (header.lib_version_ext) > MINILZO_VERSION)
+    {
+      grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
+		  "unsupported (too new) LZO version");
+      return 0;
+    }
+
+  flags = grub_be_to_cpu32 (header.flags);
+
+  if (flags & F_CRC32_D)
+    {
+      lzopio->has_ucheck = 1;
+      lzopio->ucheck_fun = grub_crypto_lookup_md_by_name ("crc32");
+    }
+  else if (flags & F_ADLER32_D)
+    {
+      lzopio->has_ucheck = 1;
+      lzopio->ucheck_fun = grub_crypto_lookup_md_by_name ("adler32");
+    }
+
+  if (flags & F_CRC32_C)
+    {
+      lzopio->has_ccheck = 1;
+      lzopio->ccheck_fun = grub_crypto_lookup_md_by_name ("crc32");
+    }
+  else if (flags & F_ADLER32_C)
+    {
+      lzopio->has_ccheck = 1;
+      lzopio->ccheck_fun = grub_crypto_lookup_md_by_name ("adler32");
+    }
+
+  if (flags & F_H_CRC32)
+    hcheck = grub_crypto_lookup_md_by_name ("crc32");
+  else
+    hcheck = grub_crypto_lookup_md_by_name ("adler32");
+
+  if (hcheck) {
+    context = grub_malloc(hcheck->contextsize);
+    if (! context)
+      return 0;
+
+    hcheck->init(context);
+
+    /* MAGIC is not included in check calculation.  */
+    hcheck->write(context, &header.lzop_version, sizeof(header)- LZOP_MAGIC_SIZE);
+  }
+
+  if (header.name_len != 0)
+    {
+      name = grub_malloc (header.name_len);
+      if (! name)
+	{
+	  grub_free (context);
+	  return 0;
+	}
+
+      if (grub_file_read (lzopio->file, name, header.name_len) !=
+	  header.name_len)
+	{
+	  grub_free(name);
+	  goto CORRUPTED;
+	}
+
+      if (hcheck)
+	hcheck->write(context, name, header.name_len);
+
+      grub_free(name);
+    }
+
+  if (hcheck)
+    hcheck->final(context);
+
+  if (grub_file_read (lzopio->file, &checksum, sizeof (checksum)) !=
+      sizeof (checksum))
+    goto CORRUPTED;
+
+  if (hcheck)
+  {
+    checksum = grub_cpu_to_be32(checksum);
+    if (grub_memcmp (&checksum, hcheck->read(context), sizeof(checksum)) != 0)
+      goto CORRUPTED;
+  }
+
+  lzopio->start_block_off = grub_file_tell (lzopio->file);
+
+  if (calculate_uncompressed_size (file) < 0)
+    goto CORRUPTED;
+
+  /* Get back to start block.  */
+  grub_file_seek (lzopio->file, lzopio->start_block_off);
+
+  /* Read first block - grub_lzopio_read() expects valid block.  */
+  if (read_block_header (lzopio) < 0)
+    goto CORRUPTED;
+
+  lzopio->saved_off = 0;
+  return 1;
+
+CORRUPTED:
+  grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, "lzop file corrupted");
+
+  grub_free(name);
+
+  return 0;
+}
+
+static grub_file_t
+grub_lzopio_open (grub_file_t io)
+{
+  grub_file_t file;
+  grub_lzopio_t lzopio;
+
+  file = (grub_file_t) grub_zalloc (sizeof (*file));
+  if (!file)
+    return 0;
+
+  lzopio = grub_zalloc (sizeof (*lzopio));
+  if (!lzopio)
+    {
+      grub_free (file);
+      return 0;
+    }
+
+  lzopio->file = io;
+
+  file->device = io->device;
+  file->offset = 0;
+  file->data = lzopio;
+  file->read_hook = 0;
+  file->fs = &grub_lzopio_fs;
+  file->size = GRUB_FILE_SIZE_UNKNOWN;
+  file->not_easily_seekable = 1;
+
+  if (grub_file_tell (lzopio->file) != 0)
+    grub_file_seek (lzopio->file, 0);
+
+  if (!test_header (file))
+    {
+      grub_errno = GRUB_ERR_NONE;
+      grub_file_seek (io, 0);
+      grub_free (lzopio);
+      grub_free (file);
+
+      return io;
+    }
+
+  return file;
+}
+
+static grub_ssize_t
+grub_lzopio_read (grub_file_t file, char *buf, grub_size_t len)
+{
+  grub_lzopio_t lzopio = file->data;
+  grub_ssize_t ret = 0;
+  grub_off_t off;
+
+  /* Backward seek before last read block.  */
+  if (lzopio->saved_off > grub_file_tell (file))
+    {
+      grub_file_seek (lzopio->file, lzopio->start_block_off);
+
+      if (read_block_header (lzopio) < 0)
+	goto CORRUPTED;
+
+      lzopio->saved_off = 0;
+    }
+
+  /* Forward to first block with requested data.  */
+  while (lzopio->saved_off + lzopio->block.usize <= grub_file_tell (file))
+    {
+      /* EOF, could be possible files with unknown size.  */
+      if (lzopio->block.usize == 0)
+	return 0;
+
+      if (jump_block (lzopio) < 0)
+	goto CORRUPTED;
+    }
+
+  off = grub_file_tell (file) - lzopio->saved_off;
+
+  while (len != 0 && lzopio->block.usize != 0)
+    {
+      long to_copy;
+
+      /* Block not decompressed yet.  */
+      if (!lzopio->block.udata && uncompress_block (lzopio) < 0)
+	goto CORRUPTED;
+
+      /* Copy requested data into buffer.  */
+      to_copy = grub_min (lzopio->block.usize - off, len);
+      grub_memcpy (buf, lzopio->block.udata + off, to_copy);
+
+      len -= to_copy;
+      buf += to_copy;
+      ret += to_copy;
+      off = 0;
+
+      /* Read next block if needed.  */
+      if (len > 0 && read_block_header (lzopio) < 0)
+	goto CORRUPTED;
+    }
+
+  return ret;
+
+CORRUPTED:
+  grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, "lzop file corrupted");
+  return -1;
+}
+
+/* Release everything, including the underlying file object.  */
+static grub_err_t
+grub_lzopio_close (grub_file_t file)
+{
+  grub_lzopio_t lzopio = file->data;
+
+  grub_file_close (lzopio->file);
+  grub_free (lzopio->block.cdata);
+  grub_free (lzopio->block.udata);
+  grub_free (lzopio);
+
+  /* Device must not be closed twice.  */
+  file->device = 0;
+  return grub_errno;
+}
+
+static struct grub_fs grub_lzopio_fs = {
+  .name = "lzopio",
+  .dir = 0,
+  .open = 0,
+  .read = grub_lzopio_read,
+  .close = grub_lzopio_close,
+  .label = 0,
+  .next = 0
+};
+
+GRUB_MOD_INIT (lzopio)
+{
+  grub_file_filter_register (GRUB_FILE_FILTER_LZOPIO, grub_lzopio_open);
+}
+
+GRUB_MOD_FINI (lzopio)
+{
+  grub_file_filter_unregister (GRUB_FILE_FILTER_LZOPIO);
+}