Adding upstream version 2.06.upstream/2.06upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 441 insertions, 0 deletions

diff --git a/grub-core/fs/fshelp.c b/grub-core/fs/fshelp.c
new file mode 100644
index 0000000..a2d0d29
--- /dev/null
+++ b/grub-core/fs/fshelp.c
@@ -0,0 +1,441 @@
+/* fshelp.c -- Filesystem helper functions */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2004,2005,2006,2007,2008  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/misc.h>
+#include <grub/disk.h>
+#include <grub/fshelp.h>
+#include <grub/dl.h>
+#include <grub/i18n.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+typedef int (*iterate_dir_func) (grub_fshelp_node_t dir,
+				 grub_fshelp_iterate_dir_hook_t hook,
+				 void *data);
+typedef grub_err_t (*lookup_file_func) (grub_fshelp_node_t dir,
+					const char *name,
+					grub_fshelp_node_t *foundnode,
+					enum grub_fshelp_filetype *foundtype);
+typedef char *(*read_symlink_func) (grub_fshelp_node_t node);
+
+struct stack_element {
+  struct stack_element *parent;
+  grub_fshelp_node_t node;
+  enum grub_fshelp_filetype type;
+};
+
+/* Context for grub_fshelp_find_file.  */
+struct grub_fshelp_find_file_ctx
+{
+  /* Inputs.  */
+  const char *path;
+  grub_fshelp_node_t rootnode;
+
+  /* Global options. */
+  int symlinknest;
+
+  /* Current file being traversed and its parents.  */
+  struct stack_element *currnode;
+};
+
+/* Helper for find_file_iter.  */
+static void
+free_node (grub_fshelp_node_t node, struct grub_fshelp_find_file_ctx *ctx)
+{
+  if (node != ctx->rootnode)
+    grub_free (node);
+}
+
+static void
+pop_element (struct grub_fshelp_find_file_ctx *ctx)
+{
+  struct stack_element *el;
+  el = ctx->currnode;
+  ctx->currnode = el->parent;
+  free_node (el->node, ctx);
+  grub_free (el);
+}
+
+static void
+free_stack (struct grub_fshelp_find_file_ctx *ctx)
+{
+  while (ctx->currnode)
+    pop_element (ctx);
+}
+
+static void
+go_up_a_level (struct grub_fshelp_find_file_ctx *ctx)
+{
+  if (!ctx->currnode->parent)
+    return;
+  pop_element (ctx);
+}
+
+static grub_err_t
+push_node (struct grub_fshelp_find_file_ctx *ctx, grub_fshelp_node_t node, enum grub_fshelp_filetype filetype)
+{
+  struct stack_element *nst;
+  nst = grub_malloc (sizeof (*nst));
+  if (!nst)
+    return grub_errno;
+  nst->node = node;
+  nst->type = filetype & ~GRUB_FSHELP_CASE_INSENSITIVE;
+  nst->parent = ctx->currnode;
+  ctx->currnode = nst;
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+go_to_root (struct grub_fshelp_find_file_ctx *ctx)
+{
+  free_stack (ctx);
+  return push_node (ctx, ctx->rootnode, GRUB_FSHELP_DIR);
+}
+
+struct grub_fshelp_find_file_iter_ctx
+{
+  const char *name;
+  grub_fshelp_node_t *foundnode;
+  enum grub_fshelp_filetype *foundtype;
+};
+
+/* Helper for grub_fshelp_find_file.  */
+static int
+find_file_iter (const char *filename, enum grub_fshelp_filetype filetype,
+		grub_fshelp_node_t node, void *data)
+{
+  struct grub_fshelp_find_file_iter_ctx *ctx = data;
+
+  if (filetype == GRUB_FSHELP_UNKNOWN ||
+      ((filetype & GRUB_FSHELP_CASE_INSENSITIVE)
+       ? grub_strcasecmp (ctx->name, filename)
+       : grub_strcmp (ctx->name, filename)))
+    {
+      grub_free (node);
+      return 0;
+    }
+
+  /* The node is found, stop iterating over the nodes.  */
+  *ctx->foundnode = node;
+  *ctx->foundtype = filetype;
+  return 1;
+}
+
+static grub_err_t
+directory_find_file (grub_fshelp_node_t node, const char *name, grub_fshelp_node_t *foundnode,
+		     enum grub_fshelp_filetype *foundtype, iterate_dir_func iterate_dir)
+{
+  int found;
+  struct grub_fshelp_find_file_iter_ctx ctx = {
+    .foundnode = foundnode,
+    .foundtype = foundtype,
+    .name = name
+  };
+  found = iterate_dir (node, find_file_iter, &ctx);
+  if (! found)
+    {
+      if (grub_errno)
+	return grub_errno;
+    }
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+find_file (char *currpath,
+	   iterate_dir_func iterate_dir, lookup_file_func lookup_file,
+	   read_symlink_func read_symlink,
+	   struct grub_fshelp_find_file_ctx *ctx)
+{
+  char *name, *next;
+  grub_err_t err;
+  for (name = currpath; ; name = next)
+    {
+      char c;
+      grub_fshelp_node_t foundnode = NULL;
+      enum grub_fshelp_filetype foundtype = 0;
+
+      /* Remove all leading slashes.  */
+      while (*name == '/')
+	name++;
+
+      /* Found the node!  */
+      if (! *name)
+	return 0;
+
+      /* Extract the actual part from the pathname.  */
+      for (next = name; *next && *next != '/'; next++);
+
+      /* At this point it is expected that the current node is a
+	 directory, check if this is true.  */
+      if (ctx->currnode->type != GRUB_FSHELP_DIR)
+	return grub_error (GRUB_ERR_BAD_FILE_TYPE, N_("not a directory"));
+
+      /* Don't rely on fs providing actual . in the listing.  */
+      if (next - name == 1 && name[0] == '.')
+	continue;
+
+      /* Don't rely on fs providing actual .. in the listing.  */
+      if (next - name == 2 && name[0] == '.' && name[1] == '.')
+	{
+	  go_up_a_level (ctx);
+	  continue;
+	}
+
+      /* Iterate over the directory.  */
+      c = *next;
+      *next = '\0';
+      if (lookup_file)
+	err = lookup_file (ctx->currnode->node, name, &foundnode, &foundtype);
+      else
+	err = directory_find_file (ctx->currnode->node, name, &foundnode, &foundtype, iterate_dir);
+      *next = c;
+
+      if (err)
+	return err;
+
+      if (!foundnode)
+	break;
+
+      push_node (ctx, foundnode, foundtype);
+ 
+      /* Read in the symlink and follow it.  */
+      if (ctx->currnode->type == GRUB_FSHELP_SYMLINK)
+	{
+	  char *symlink;
+
+	  /* Test if the symlink does not loop.  */
+	  if (++ctx->symlinknest == 8)
+	    return grub_error (GRUB_ERR_SYMLINK_LOOP,
+			       N_("too deep nesting of symlinks"));
+
+	  symlink = read_symlink (ctx->currnode->node);
+
+	  if (!symlink)
+	    return grub_errno;
+
+	  /* The symlink is an absolute path, go back to the root inode.  */
+	  if (symlink[0] == '/')
+	    {
+	      err = go_to_root (ctx);
+	      if (err)
+		return err;
+	    }
+	  else
+	    {
+	      /* Get from symlink to containing directory. */
+	      go_up_a_level (ctx);
+	    }
+
+
+	  /* Lookup the node the symlink points to.  */
+	  find_file (symlink, iterate_dir, lookup_file, read_symlink, ctx);
+	  grub_free (symlink);
+
+	  if (grub_errno)
+	    return grub_errno;
+	}
+    }
+
+  return grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("file `%s' not found"),
+		     ctx->path);
+}
+
+static grub_err_t
+grub_fshelp_find_file_real (const char *path, grub_fshelp_node_t rootnode,
+			    grub_fshelp_node_t *foundnode,
+			    iterate_dir_func iterate_dir,
+			    lookup_file_func lookup_file,
+			    read_symlink_func read_symlink,
+			    enum grub_fshelp_filetype expecttype)
+{
+  struct grub_fshelp_find_file_ctx ctx = {
+    .path = path,
+    .rootnode = rootnode,
+    .symlinknest = 0,
+    .currnode = 0
+  };
+  grub_err_t err;
+  enum grub_fshelp_filetype foundtype;
+  char *duppath;
+
+  if (!path || path[0] != '/')
+    {
+      return grub_error (GRUB_ERR_BAD_FILENAME, N_("invalid file name `%s'"), path);
+    }
+
+  err = go_to_root (&ctx);
+  if (err)
+    return err;
+
+  duppath = grub_strdup (path);
+  if (!duppath)
+    return grub_errno;
+  err = find_file (duppath, iterate_dir, lookup_file, read_symlink, &ctx);
+  grub_free (duppath);
+  if (err)
+    {
+      free_stack (&ctx);
+      return err;
+    }
+
+  *foundnode = ctx.currnode->node;
+  foundtype = ctx.currnode->type;
+  /* Avoid the node being freed.  */
+  ctx.currnode->node = 0;
+  free_stack (&ctx);
+
+  /* Check if the node that was found was of the expected type.  */
+  if (expecttype == GRUB_FSHELP_REG && foundtype != expecttype)
+    return grub_error (GRUB_ERR_BAD_FILE_TYPE, N_("not a regular file"));
+  else if (expecttype == GRUB_FSHELP_DIR && foundtype != expecttype)
+    return grub_error (GRUB_ERR_BAD_FILE_TYPE, N_("not a directory"));
+
+  return 0;
+}
+
+/* Lookup the node PATH.  The node ROOTNODE describes the root of the
+   directory tree.  The node found is returned in FOUNDNODE, which is
+   either a ROOTNODE or a new malloc'ed node.  ITERATE_DIR is used to
+   iterate over all directory entries in the current node.
+   READ_SYMLINK is used to read the symlink if a node is a symlink.
+   EXPECTTYPE is the type node that is expected by the called, an
+   error is generated if the node is not of the expected type.  */
+grub_err_t
+grub_fshelp_find_file (const char *path, grub_fshelp_node_t rootnode,
+		       grub_fshelp_node_t *foundnode,
+		       iterate_dir_func iterate_dir,
+		       read_symlink_func read_symlink,
+		       enum grub_fshelp_filetype expecttype)
+{
+  return grub_fshelp_find_file_real (path, rootnode, foundnode,
+				     iterate_dir, NULL, 
+				     read_symlink, expecttype);
+
+}
+
+grub_err_t
+grub_fshelp_find_file_lookup (const char *path, grub_fshelp_node_t rootnode,
+			      grub_fshelp_node_t *foundnode,
+			      lookup_file_func lookup_file,
+			      read_symlink_func read_symlink,
+			      enum grub_fshelp_filetype expecttype)
+{
+  return grub_fshelp_find_file_real (path, rootnode, foundnode,
+				     NULL, lookup_file, 
+				     read_symlink, expecttype);
+
+}
+
+/* Read LEN bytes from the file NODE on disk DISK into the buffer BUF,
+   beginning with the block POS.  READ_HOOK should be set before
+   reading a block from the file.  READ_HOOK_DATA is passed through as
+   the DATA argument to READ_HOOK.  GET_BLOCK is used to translate
+   file blocks to disk blocks.  The file is FILESIZE bytes big and the
+   blocks have a size of LOG2BLOCKSIZE (in log2).  */
+grub_ssize_t
+grub_fshelp_read_file (grub_disk_t disk, 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,
+		       grub_disk_addr_t (*get_block) (grub_fshelp_node_t node,
+                                                      grub_disk_addr_t block),
+		       grub_off_t filesize, int log2blocksize,
+		       grub_disk_addr_t blocks_start)
+{
+  grub_disk_addr_t i, blockcnt;
+  int blocksize = 1 << (log2blocksize + GRUB_DISK_SECTOR_BITS);
+
+  /*
+   * Catch blatantly invalid log2blocksize. We could be a lot stricter, but
+   * this is the most permissive we can be before we start to see integer
+   * overflow/underflow issues.
+   */
+  if (log2blocksize + GRUB_DISK_SECTOR_BITS >= 31)
+    {
+      grub_error (GRUB_ERR_OUT_OF_RANGE,
+		  N_("blocksize too large"));
+      return -1;
+    }
+
+  if (pos > filesize)
+    {
+      grub_error (GRUB_ERR_OUT_OF_RANGE,
+		  N_("attempt to read past the end of file"));
+      return -1;
+    }
+
+  /* Adjust LEN so it we can't read past the end of the file.  */
+  if (pos + len > filesize)
+    len = filesize - pos;
+
+  blockcnt = ((len + pos) + blocksize - 1) >> (log2blocksize + GRUB_DISK_SECTOR_BITS);
+
+  for (i = pos >> (log2blocksize + GRUB_DISK_SECTOR_BITS); i < blockcnt; i++)
+    {
+      grub_disk_addr_t blknr;
+      int blockoff = pos & (blocksize - 1);
+      int blockend = blocksize;
+
+      int skipfirst = 0;
+
+      blknr = get_block (node, i);
+      if (grub_errno)
+	return -1;
+
+      blknr = blknr << log2blocksize;
+
+      /* Last block.  */
+      if (i == blockcnt - 1)
+	{
+	  blockend = (len + pos) & (blocksize - 1);
+
+	  /* The last portion is exactly blocksize.  */
+	  if (! blockend)
+	    blockend = blocksize;
+	}
+
+      /* First block.  */
+      if (i == (pos >> (log2blocksize + GRUB_DISK_SECTOR_BITS)))
+	{
+	  skipfirst = blockoff;
+	  blockend -= skipfirst;
+	}
+
+      /* If the block number is 0 this block is not stored on disk but
+	 is zero filled instead.  */
+      if (blknr)
+	{
+	  disk->read_hook = read_hook;
+	  disk->read_hook_data = read_hook_data;
+
+	  grub_disk_read (disk, blknr + blocks_start, skipfirst,
+			  blockend, buf);
+	  disk->read_hook = 0;
+	  if (grub_errno)
+	    return -1;
+	}
+      else
+	grub_memset (buf, 0, blockend);
+
+      buf += blocksize - skipfirst;
+    }
+
+  return len;
+}