1 files changed, 134 insertions, 0 deletions
diff --git a/procfs/procfs_dir.c b/procfs/procfs_dir.c
new file mode 100644
index 00000000..c250aa48
--- /dev/null
+++ b/procfs/procfs_dir.c
@@ -0,0 +1,134 @@
+/* Hurd /proc filesystem, infrastructure for directories.
+   Copyright (C) 2010 Free Software Foundation, Inc.
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd 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 2, or (at
+   your option) any later version.
+
+   The GNU Hurd 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 this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include <stdlib.h>
+#include <string.h>
+#include "procfs.h"
+#include "procfs_dir.h"
+
+struct procfs_dir_node
+{
+  const struct procfs_dir_ops *ops;
+  void *hook;
+};
+
+static int
+entry_exists (struct procfs_dir_node *dir, const struct procfs_dir_entry *ent)
+{
+  if (ent->ops.exists)
+    return ent->ops.exists (dir->hook, ent->hook);
+  if (dir->ops->entry_ops.exists)
+    return dir->ops->entry_ops.exists (dir->hook, ent->hook);
+
+  return 1;
+}
+
+static error_t
+procfs_dir_get_contents (void *hook, char **contents, ssize_t *contents_len)
+{
+  static const char dot_dotdot[] = ".\0..";
+  struct procfs_dir_node *dir = hook;
+  const struct procfs_dir_entry *ent;
+  int pos;
+
+  /* Evaluate how much space is needed.  Note that we include the hidden
+     entries, just in case their status changes between now and then.  */
+  pos = sizeof dot_dotdot;
+  for (ent = dir->ops->entries; ent->name; ent++)
+    pos += strlen (ent->name) + 1;
+
+  *contents = malloc (pos);
+  if (! *contents)
+    return ENOMEM;
+
+  memcpy (*contents, dot_dotdot, sizeof dot_dotdot);
+  pos = sizeof dot_dotdot;
+  for (ent = dir->ops->entries; ent->name; ent++)
+    {
+      if (! entry_exists (dir, ent))
+	continue;
+
+      strcpy (*contents + pos, ent->name);
+      pos += strlen (ent->name) + 1;
+    }
+
+  *contents_len = pos;
+  return 0;
+}
+
+static error_t
+procfs_dir_lookup (void *hook, const char *name, struct node **np)
+{
+  struct procfs_dir_node *dir = hook;
+  const struct procfs_dir_entry *ent;
+
+  for (ent = dir->ops->entries; ent->name && strcmp (name, ent->name); ent++);
+  if (! ent->name)
+    return ENOENT;
+
+  if (ent->ops.make_node)
+    *np = ent->ops.make_node (dir->hook, ent->hook);
+  else if (dir->ops->entry_ops.make_node)
+    *np = dir->ops->entry_ops.make_node (dir->hook, ent->hook);
+  else
+    return EGRATUITOUS;
+
+  if (! *np)
+    return ENOMEM;
+
+  return 0;
+}
+
+static void
+procfs_dir_cleanup (void *hook)
+{
+  struct procfs_dir_node *dir = hook;
+
+  if (dir->ops->cleanup)
+    dir->ops->cleanup (dir->hook);
+
+  free (dir);
+}
+
+struct node *
+procfs_dir_make_node (const struct procfs_dir_ops *dir_ops, void *dir_hook)
+{
+  static const struct procfs_node_ops ops = {
+    .get_contents = procfs_dir_get_contents,
+    .lookup = procfs_dir_lookup,
+    .cleanup_contents = procfs_cleanup_contents_with_free,
+    .cleanup = procfs_dir_cleanup,
+  };
+  struct procfs_dir_node *dir;
+
+  dir = malloc (sizeof *dir);
+  if (! dir)
+    {
+      if (dir_ops->cleanup)
+	dir_ops->cleanup (dir_hook);
+
+      return NULL;
+    }
+
+  dir->ops = dir_ops;
+  dir->hook = dir_hook;
+
+  return procfs_make_node (&ops, dir);
+}
+