NetBSD/dist/dhcp/common/memory.c

169 lines
5.7 KiB
C

/* memory.c
Memory-resident database... */
/*
* Copyright (c) 1995-2002 Internet Software Consortium.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of The Internet Software Consortium nor the names
* of its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
* CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This software has been written for the Internet Software Consortium
* by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
* To learn more about the Internet Software Consortium, see
* ``http://www.isc.org/''. To learn more about Vixie Enterprises,
* see ``http://www.vix.com''. To learn more about Nominum, Inc., see
* ``http://www.nominum.com''.
*/
#ifndef lint
static char copyright[] =
"$Id: memory.c,v 1.4 2003/02/18 17:08:41 drochner Exp $ Copyright (c) 1995-2002 The Internet Software Consortium. All rights reserved.\n";
#endif /* not lint */
#include "dhcpd.h"
struct group *root_group;
group_hash_t *group_name_hash;
int (*group_write_hook) (struct group_object *);
isc_result_t delete_group (struct group_object *group, int writep)
{
struct group_object *d;
/* The group should exist and be hashed - if not, it's invalid. */
if (group_name_hash) {
d = (struct group_object *)0;
group_hash_lookup (&d, group_name_hash, group -> name,
strlen (group -> name), MDL);
} else
return ISC_R_INVALIDARG;
if (!d)
return ISC_R_INVALIDARG;
/* Also not okay to delete a group that's not the one in
the hash table. */
if (d != group)
return ISC_R_INVALIDARG;
/* If it's dynamic, and we're deleting it, we can just blow away the
hash table entry. */
if ((group -> flags & GROUP_OBJECT_DYNAMIC) &&
!(group -> flags & GROUP_OBJECT_STATIC)) {
group_hash_delete (group_name_hash,
group -> name, strlen (group -> name), MDL);
} else {
group -> flags |= GROUP_OBJECT_DELETED;
if (group -> group)
group_dereference (&group -> group, MDL);
}
/* Store the group declaration in the lease file. */
if (writep && group_write_hook) {
if (!(*group_write_hook) (group))
return ISC_R_IOERROR;
}
return ISC_R_SUCCESS;
}
isc_result_t supersede_group (struct group_object *group, int writep)
{
struct group_object *t;
/* Register the group in the group name hash table,
so we can look it up later. */
if (group_name_hash) {
t = (struct group_object *)0;
group_hash_lookup (&t, group_name_hash,
group -> name,
strlen (group -> name), MDL);
if (t && t != group) {
/* If this isn't a dynamic entry, then we need to flag
the replacement as not dynamic either - otherwise,
if the dynamic entry is deleted later, the static
entry will come back next time the server is stopped
and restarted. */
if (!(t -> flags & GROUP_OBJECT_DYNAMIC))
group -> flags |= GROUP_OBJECT_STATIC;
/* Delete the old object if it hasn't already been
deleted. If it has already been deleted, get rid of
the hash table entry. This is a legitimate
situation - a deleted static object needs to be kept
around so we remember it's deleted. */
if (!(t -> flags & GROUP_OBJECT_DELETED))
delete_group (t, 0);
else {
group_hash_delete (group_name_hash,
group -> name,
strlen (group -> name),
MDL);
group_object_dereference (&t, MDL);
}
}
} else {
group_new_hash (&group_name_hash, 0, MDL);
t = (struct group_object *)0;
}
/* Add the group to the group name hash if it's not
already there, and also thread it into the list of
dynamic groups if appropriate. */
if (!t) {
group_hash_add (group_name_hash, group -> name,
strlen (group -> name), group, MDL);
}
/* Store the group declaration in the lease file. */
if (writep && group_write_hook) {
if (!(*group_write_hook) (group))
return ISC_R_IOERROR;
}
return ISC_R_SUCCESS;
}
int clone_group (struct group **gp, struct group *group,
const char *file, int line)
{
struct group *g = (struct group *)0;
/* Normally gp should contain the null pointer, but for convenience
it's permissible to clone a group into itself. */
if (*gp && *gp != group)
return 0;
if (!group_allocate (&g, file, line))
return 0;
if (group == *gp)
*gp = (struct group *)0;
group_reference (gp, g, file, line);
g -> authoritative = group -> authoritative;
group_reference (&g -> next, group, file, line);
group_dereference (&g, file, line);
return 1;
}