Adding upstream version 2.06.upstream/2.06upstream

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

1 files changed, 238 insertions, 0 deletions

diff --git a/grub-core/kern/env.c b/grub-core/kern/env.c
new file mode 100644
index 0000000..c408626
--- /dev/null
+++ b/grub-core/kern/env.c
@@ -0,0 +1,238 @@
+/* env.c - Environment variables */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2003,2005,2006,2007,2008,2009  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/env.h>
+#include <grub/env_private.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+
+/* The initial context.  */
+static struct grub_env_context initial_context;
+
+/* The current context.  */
+struct grub_env_context *grub_current_context = &initial_context;
+
+/* Return the hash representation of the string S.  */
+static unsigned int
+grub_env_hashval (const char *s)
+{
+  unsigned int i = 0;
+
+  /* XXX: This can be done much more efficiently.  */
+  while (*s)
+    i += 5 * *(s++);
+
+  return i % HASHSZ;
+}
+
+static struct grub_env_var *
+grub_env_find (const char *name)
+{
+  struct grub_env_var *var;
+  int idx = grub_env_hashval (name);
+
+  /* Look for the variable in the current context.  */
+  for (var = grub_current_context->vars[idx]; var; var = var->next)
+    if (grub_strcmp (var->name, name) == 0)
+      return var;
+
+  return 0;
+}
+
+static void
+grub_env_insert (struct grub_env_context *context,
+		 struct grub_env_var *var)
+{
+  int idx = grub_env_hashval (var->name);
+
+  /* Insert the variable into the hashtable.  */
+  var->prevp = &context->vars[idx];
+  var->next = context->vars[idx];
+  if (var->next)
+    var->next->prevp = &(var->next);
+  context->vars[idx] = var;
+}
+
+static void
+grub_env_remove (struct grub_env_var *var)
+{
+  /* Remove the entry from the variable table.  */
+  *var->prevp = var->next;
+  if (var->next)
+    var->next->prevp = var->prevp;
+}
+
+grub_err_t
+grub_env_set (const char *name, const char *val)
+{
+  struct grub_env_var *var;
+
+  /* If the variable does already exist, just update the variable.  */
+  var = grub_env_find (name);
+  if (var)
+    {
+      char *old = var->value;
+
+      if (var->write_hook)
+	var->value = var->write_hook (var, val);
+      else
+	var->value = grub_strdup (val);
+
+      if (! var->value)
+	{
+	  var->value = old;
+	  return grub_errno;
+	}
+
+      grub_free (old);
+      return GRUB_ERR_NONE;
+    }
+
+  /* The variable does not exist, so create a new one.  */
+  var = grub_zalloc (sizeof (*var));
+  if (! var)
+    return grub_errno;
+
+  var->name = grub_strdup (name);
+  if (! var->name)
+    goto fail;
+
+  var->value = grub_strdup (val);
+  if (! var->value)
+    goto fail;
+
+  grub_env_insert (grub_current_context, var);
+
+  return GRUB_ERR_NONE;
+
+ fail:
+  grub_free (var->name);
+  grub_free (var->value);
+  grub_free (var);
+
+  return grub_errno;
+}
+
+const char *
+grub_env_get (const char *name)
+{
+  struct grub_env_var *var;
+
+  var = grub_env_find (name);
+  if (! var)
+    return 0;
+
+  if (var->read_hook)
+    return var->read_hook (var, var->value);
+
+  return var->value;
+}
+
+void
+grub_env_unset (const char *name)
+{
+  struct grub_env_var *var;
+
+  var = grub_env_find (name);
+  if (! var)
+    return;
+
+  if (var->read_hook || var->write_hook)
+    {
+      grub_env_set (name, "");
+      return;
+    }
+
+  grub_env_remove (var);
+
+  grub_free (var->name);
+  grub_free (var->value);
+  grub_free (var);
+}
+
+struct grub_env_var *
+grub_env_update_get_sorted (void)
+{
+  struct grub_env_var *sorted_list = 0;
+  int i;
+
+  /* Add variables associated with this context into a sorted list.  */
+  for (i = 0; i < HASHSZ; i++)
+    {
+      struct grub_env_var *var;
+
+      for (var = grub_current_context->vars[i]; var; var = var->next)
+	{
+	  struct grub_env_var *p, **q;
+
+	  for (q = &sorted_list, p = *q; p; q = &((*q)->sorted_next), p = *q)
+	    {
+	      if (grub_strcmp (p->name, var->name) > 0)
+		break;
+	    }
+
+	  var->sorted_next = *q;
+	  *q = var;
+	}
+    }
+
+  return sorted_list;
+}
+
+grub_err_t
+grub_register_variable_hook (const char *name,
+			     grub_env_read_hook_t read_hook,
+			     grub_env_write_hook_t write_hook)
+{
+  struct grub_env_var *var = grub_env_find (name);
+
+  if (! var)
+    {
+      if (grub_env_set (name, "") != GRUB_ERR_NONE)
+	return grub_errno;
+
+      var = grub_env_find (name);
+      /* XXX Insert an assertion?  */
+    }
+
+  var->read_hook = read_hook;
+  var->write_hook = write_hook;
+
+  return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_env_export (const char *name)
+{
+  struct grub_env_var *var;
+
+  var = grub_env_find (name);
+  if (! var)
+    {
+      grub_err_t err;
+      
+      err = grub_env_set (name, "");
+      if (err)
+	return err;
+      var = grub_env_find (name);
+    }    
+  var->global = 1;
+
+  return GRUB_ERR_NONE;
+}