initial commit

GRUB2/grub-2.04/grub-core/kern/file.c

@@ -0,0 +1,256 @@
+/* file.c - file I/O functions */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2002,2006,2007,2009  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/misc.h>
+#include <grub/err.h>
+#include <grub/file.h>
+#include <grub/net.h>
+#include <grub/mm.h>
+#include <grub/fs.h>
+#include <grub/device.h>
+#include <grub/i18n.h>
+
+void (*EXPORT_VAR (grub_grubnet_fini)) (void);
+
+grub_file_filter_t grub_file_filters[GRUB_FILE_FILTER_MAX];
+
+/* Get the device part of the filename NAME. It is enclosed by parentheses.  */
+char *
+grub_file_get_device_name (const char *name)
+{
+  if (name[0] == '(')
+    {
+      char *p = grub_strchr (name, ')');
+      char *ret;
+
+      if (! p)
+	{
+	  grub_error (GRUB_ERR_BAD_FILENAME, N_("missing `%c' symbol"), ')');
+	  return 0;
+	}
+
+      ret = (char *) grub_malloc (p - name);
+      if (! ret)
+	return 0;
+
+      grub_memcpy (ret, name + 1, p - name - 1);
+      ret[p - name - 1] = '\0';
+      return ret;
+    }
+
+  return 0;
+}
+
+/* Support mem:xxx:size:xxx format in chainloader */
+grub_file_t grub_memfile_open(const char *name);
+#define GRUB_MEMFILE_MEM     "mem:"
+#define GRUB_MEMFILE_SIZE    "size:"
+
+grub_file_t grub_memfile_open(const char *name)
+{
+    char *size = NULL;
+    grub_file_t file = 0;
+    
+    file = (grub_file_t)grub_zalloc(sizeof(*file));
+    if (NULL == file)
+    {
+        return 0;
+    }
+
+    file->name = grub_strdup(name);
+    file->data = (void *)grub_strtoul(name + grub_strlen(GRUB_MEMFILE_MEM), NULL, 0);
+
+    size = grub_strstr(name, GRUB_MEMFILE_SIZE);
+    file->size = (grub_off_t)grub_strtoul(size + grub_strlen(GRUB_MEMFILE_SIZE), NULL, 0);
+
+    grub_errno = GRUB_ERR_NONE;
+    return file;
+}
+
+grub_file_t
+grub_file_open (const char *name, enum grub_file_type type)
+{
+  grub_device_t device = 0;
+  grub_file_t file = 0, last_file = 0;
+  char *device_name;
+  const char *file_name;
+  grub_file_filter_id_t filter;
+
+  /* <DESC> : mem:xxx:size:xxx format in chainloader */
+  if (grub_strncmp(name, GRUB_MEMFILE_MEM, grub_strlen(GRUB_MEMFILE_MEM)) == 0) {
+      return grub_memfile_open(name);
+  }  
+
+  device_name = grub_file_get_device_name (name);
+  if (grub_errno)
+    goto fail;
+
+  /* Get the file part of NAME.  */
+  file_name = (name[0] == '(') ? grub_strchr (name, ')') : NULL;
+  if (file_name)
+    file_name++;
+  else
+    file_name = name;
+
+  device = grub_device_open (device_name);
+  grub_free (device_name);
+  if (! device)
+    goto fail;
+
+  file = (grub_file_t) grub_zalloc (sizeof (*file));
+  if (! file)
+    goto fail;
+
+  file->device = device;
+
+  /* In case of relative pathnames and non-Unix systems (like Windows)
+   * name of host files may not start with `/'. Blocklists for host files
+   * are meaningless as well (for a start, host disk does not allow any direct
+   * access - it is just a marker). So skip host disk in this case.
+   */
+  if (device->disk && file_name[0] != '/'
+#if defined(GRUB_UTIL) || defined(GRUB_MACHINE_EMU)
+      && grub_strcmp (device->disk->name, "host")
+#endif
+     )
+    /* This is a block list.  */
+    file->fs = &grub_fs_blocklist;
+  else
+    {
+      file->fs = grub_fs_probe (device);
+      if (! file->fs)
+	goto fail;
+    }
+
+  if ((file->fs->fs_open) (file, file_name) != GRUB_ERR_NONE)
+    goto fail;
+
+  file->name = grub_strdup (name);
+  grub_errno = GRUB_ERR_NONE;
+
+  for (filter = 0; file && filter < ARRAY_SIZE (grub_file_filters);
+       filter++)
+    if (grub_file_filters[filter])
+      {
+	last_file = file;
+	file = grub_file_filters[filter] (file, type);
+	if (file && file != last_file)
+	  {
+	    file->name = grub_strdup (name);
+	    grub_errno = GRUB_ERR_NONE;
+	  }
+      }
+  if (!file)
+    grub_file_close (last_file);
+
+  return file;
+
+ fail:
+  if (device)
+    grub_device_close (device);
+
+  /* if (net) grub_net_close (net);  */
+
+  grub_free (file);
+
+  return 0;
+}
+
+grub_disk_read_hook_t grub_file_progress_hook;
+
+grub_ssize_t
+grub_file_read (grub_file_t file, void *buf, grub_size_t len)
+{
+  grub_ssize_t res;
+  grub_disk_read_hook_t read_hook;
+  void *read_hook_data;
+
+  if (file->offset > file->size)
+    {
+      grub_error (GRUB_ERR_OUT_OF_RANGE,
+		  N_("attempt to read past the end of file"));
+      return -1;
+    }
+
+  if (len == 0)
+    return 0;
+
+  if (len > file->size - file->offset)
+    len = file->size - file->offset;
+
+  /* Prevent an overflow.  */
+  if ((grub_ssize_t) len < 0)
+    len >>= 1;
+
+  if (len == 0)
+    return 0;
+
+  if (grub_strncmp(file->name, GRUB_MEMFILE_MEM, grub_strlen(GRUB_MEMFILE_MEM)) == 0) {
+      grub_memcpy(buf, (grub_uint8_t *)(file->data) + file->offset, len);
+      file->offset += len;
+      return len;
+  }
+  
+  read_hook = file->read_hook;
+  read_hook_data = file->read_hook_data;
+  if (!file->read_hook)
+    {
+      file->read_hook = grub_file_progress_hook;
+      file->read_hook_data = file;
+      file->progress_offset = file->offset;
+    }
+  res = (file->fs->fs_read) (file, buf, len);
+  file->read_hook = read_hook;
+  file->read_hook_data = read_hook_data;
+  if (res > 0)
+    file->offset += res;
+
+  return res;
+}
+
+grub_err_t
+grub_file_close (grub_file_t file)
+{
+  if (file->fs && file->fs->fs_close)
+    (file->fs->fs_close) (file);
+
+  if (file->device)
+    grub_device_close (file->device);
+  grub_free (file->name);
+  grub_free (file);
+  return grub_errno;
+}
+
+grub_off_t
+grub_file_seek (grub_file_t file, grub_off_t offset)
+{
+  grub_off_t old;
+
+  if (offset > file->size)
+    {
+      grub_error (GRUB_ERR_OUT_OF_RANGE,
+		  N_("attempt to seek outside of the file"));
+      return -1;
+    }
+  
+  old = file->offset;
+  file->offset = offset;
+    
+  return old;
+}