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/* 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);
}
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